JPH0612207B2 - Absorption heat pump controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention is directed to pumping the heat of a low-temperature fluid such as waste steam discharged from a chemical plant or hot water discharged from a factory to generate hot water or steam having a temperature higher than that of the low-temperature fluid. The present invention relates to an absorption heat pump for taking out a fluid to be heated, and more particularly to a control device for an absorption heat pump having a plurality of evaporators and an absorber (hereinafter referred to as this kind of absorption heat pump).

(B) Prior art This type of absorption heat pump is disclosed in, for example, Japanese Patent Publication No. 58-185.
It is conventionally known as described in Japanese Patent Publication No. 74-74.

In this type of absorption heat pump, the amount and temperature of discharged hot water or the amount and temperature of cooling water usually fluctuate depending on the operating conditions of the factory.Therefore, the evaporation amount of the refrigerant in the generator and the condenser The operating state of the absorption heat pump changes due to fluctuations in the amount of condensed refrigerant in the system, and the temperature of the hot water taken out from the absorber tends to change. Then, in this type of absorption heat pump, in order to reduce the temperature fluctuation of the hot water taken out from the absorber, the amount of the refrigerant liquid sent to the evaporator is adjusted to reduce the fluctuation of the refrigerant vapor amount flowing from the evaporator to the absorber. It is necessary to reduce the fluctuation of the heat radiation amount of the absorber.

However, this type of conventional absorption heat pump (Japanese Patent Publication Sho 58
(See Japanese Patent Publication No. 18574), a pump for sending the refrigerant liquid from the condenser to each evaporator is shared by one pump, so that the flow rate control valve for the refrigerant liquid provided on one evaporator side is narrowed, for example. In this case, the refrigerant liquid discharged by the pump largely flows to the other evaporator side. In other words, if the amount of refrigerant liquid sprayed to one evaporator is adjusted, the amount of refrigerant liquid sprayed to the other evaporator fluctuates, so the operating state does not stabilize, and the temperature fluctuations of the hot water taken out from the absorber are sufficient. It has the drawback of not becoming smaller.

(C) Object of the Invention The present invention has an object to provide an absorption heat pump of this type, which is capable of reducing the temperature fluctuation of hot water and other fluids to be heated taken out from the absorber.

(D) Configuration of the invention The present invention is, in this type of absorption heat pump, a pipe for guiding the refrigerant liquid from the condenser to the high temperature side evaporator and a pipe for guiding the refrigerant liquid from the high temperature side evaporator to the low temperature side evaporator. A coolant liquid pump (hereinafter, referred to as a first pump and a second pump) is provided in each of the passages, and a refrigerant liquid flow rate control valve (hereinafter, referred to as a first and a second control) on the discharge sides of the first and second pumps. Valve) and controls the opening of the first control valve according to the amount of refrigerant liquid in the condenser and controls the opening of the second control valve according to the amount of refrigerant liquid in the evaporator on the high temperature side. It is configured.

According to the present invention, it is possible to reduce variations in the amount of refrigerant liquid sent from the condenser to the high temperature side evaporator and the amount of refrigerant liquid sent from the high temperature side evaporator to the low temperature side evaporator.
Since it is easy to stabilize the operating state, it is possible to reduce the temperature fluctuation of the fluid to be heated.

(E) Embodiment FIG. 1 is a schematic configuration explanatory view showing an embodiment of the device of the present invention. In the figure, (1) is a generator, (2) is a condenser, and (3)
Is a low temperature evaporator, (4) is an absorber, (5) is a high temperature evaporator, (6) is a high temperature absorber, (7) is a high temperature solution heat exchanger, (8) is a low temperature solution heat exchanger, and (9) ), (10), (11) are the first and
The second and third pumps, (12) are pumps for absorbing liquid, and these devices include pipes (13) and (14) through which refrigerant vapor flows, pipes (15) and (15) 'through which refrigerant liquid flows, and refrigerant. Liquid reflux tubes (16), (16) ',
(16) ″, a pipe (17) for flowing down the refrigerant liquid, and a pipe for returning the refrigerant liquid
(18), (18) ', absorption liquid flowing pipes (19), (19)' (19) ",
The absorption heat pump of this kind is constructed by connecting (19) and the pipes (20) and (21) through which the absorbing liquid flows down.

(22) is a heater built in the generator (1), (23) is a cooler built in the condenser (2), (24) is a heat supply built in the low temperature evaporator (3), (25) Is a heat exchanger built in the absorber (4), (26) is a heated unit built in the high temperature absorber (6), and (27) and (27) 'are waste steam connected to the heater (22). And (28) and (28) 'are pipes for flowing cooling water connected to the cooler (23), and (29) and (29)' are heat exchangers (24). Connected pipes for low-temperature fluid such as waste steam and waste hot water, (30), (30) 'are pipes for flowing heated fluid such as hot water and steam connected to the heater (26), and (31) , (32), (33) are condensers (2),
Refrigerant sump of high temperature evaporator (5), low temperature evaporator (3), (34), (3
5) and (36) are the generator (1), absorber (5) and high temperature absorber, respectively.
It is the solution reservoir of (6). Also, (37), (38), (39), (4
(0) and (41) are eliminators, (42) is a pipe for blowing the refrigerant liquid, and (43) is a non-condensable gas generator in the absorber (4).
A pipe for guiding the (1) side, and (44) is a pipe for guiding the non-condensable gas in the high temperature absorber (6) to the absorber (4) side. Although not shown, the pipes (43) and (44) are provided with orifices. Further, (45), (46), and (47) are the generator (1), the absorber (4), and the high-temperature absorber (6) provided with a sprayer for absorbing liquid, and (48) is a low-temperature evaporator ( This is a sprayer for the refrigerant liquid provided in 3).

(V ₁ ) is the first provided on the pipe (15) 'on the discharge side of the first pump (9)
A control valve, (V ₂ ) is a second control valve provided on the discharge side pipe (17) of the second pump (10), and (C ₁ ) is a refrigerant reservoir (3) of the condenser (2).
In the first liquid level controller provided in 1), the opening of the first control valve is increased / decreased according to the vertical movement of the liquid level of the refrigerant sump (31) by the first liquid level controller. And again, (C ₂ )
Is a second liquid level controller provided in the refrigerant liquid sump (32) of the high temperature evaporator (5). The second liquid level controller controls the second liquid level controller according to the vertical movement of the liquid level of the refrigerant liquid sump (32). 2 The opening of the control valve is adapted to be increased or decreased. In addition, these liquid level controllers (C ₁ ), (C
_{In 2} ), when the liquid level reaches the lower limit setting level, the first pump (9) and the second pump (10) are stopped, respectively.

Further, (S ₁ ) is a liquid level switch provided in the refrigerant liquid reservoir (33) of the low temperature evaporator (3), and (S ₂ ) is a liquid level switch provided in the solution reservoir (34) of the generator (1). Yes, these liquid level switches (S ₁ ), (S ₂ )
When the liquid level reaches the lower limit setting level, the pumps (11) and (12) are stopped, respectively. In addition, (V)
Is an on-off valve for blowing the refrigerant liquid provided in the pipe (42), (D) is the pipe (1
It is a damper prepared for 9) ″.

Next, the operation of the absorption heat pump (hereinafter referred to as this machine) configured as described above will be described. In the generator (1), the absorbing liquid sprinkled on the heater (22) boils due to the heat of waste vapor and other low-temperature fluids, and the refrigerant vapor is separated from the absorbing liquid.
The separated refrigerant vapor reaches the condenser (2) via the pipe (13) and is condensed in the condenser to become a refrigerant liquid. This refrigerant liquid is sent to the refrigerant liquid reservoir (32) of the high temperature evaporator (5) by the first pump (9) via the pipes (15) and (15) '. The refrigerant liquid in the refrigerant liquid reservoir (32) is supplied to the pipes (16), (16) ', (17) by the second pump (10).
Via the cryogenic evaporator (3) refrigerant reservoir (33) and pipes (16), (1
It is sent separately to the heat exchanger (25) via 6) ′. The refrigerant liquid sent to the refrigerant liquid reservoir (33) is a pipe (18) by a pump (11),
It is returned to the sprayer (48) of the low temperature evaporator (3) via (18) ′,
Sprinkled on the heater (24). The refrigerant liquid sprinkled on the heat supplier (24) is boiled by the heat of the waste vapor and other low-temperature fluid to become the refrigerant vapor. This refrigerant vapor reaches the absorber (4) via the pipe (14) and is absorbed by the absorbing liquid sprinkled on the heat exchanger (25).
The absorbing liquid that has absorbed the refrigerant vapor generates heat and raises the temperature of the refrigerant liquid in the heat exchanger (25). The heated refrigerant liquid is returned to the high temperature evaporator (5) via the pipe (16) ″, and is evaporated in this high temperature evaporator to become a refrigerant vapor. Although not shown, the pipe (16) ″
An orifice is provided in the. On the other hand, the absorption liquid concentrated in the generator (1) is transferred to the pipes (19), (1
9) ′, the low temperature solution heat exchanger (8), the pipe (19) ″, the high temperature solution heat exchanger (7), and the pipe (19) to the sprayer (47) of the high temperature absorber (6), The absorption liquid sprinkled on the device to be heated (26) absorbs the refrigerant vapor from the high temperature evaporator (5) to generate heat, and the absorption liquid in the device to be heated (26) is heated. The heated fluid such as hot water or steam drops into the solution reservoir (36) while heating.
The absorption liquid in (36) is the pipe (20), high temperature solution heat exchanger (7), pipe
It flows down to the sprayer (46) of the absorber (4) via (20). Then, the absorbing liquid is sprayed to the heat exchanger (25) to be the low temperature evaporator (3).
While absorbing the refrigerant vapor from, it falls into the solution reservoir (35).
The absorption liquid in the solution reservoir (35) is stored in the pipe (21) and low temperature solution heat exchanger.
(8) Flows down to the sprayer (45) of the generator (1) via the pipe (21) and is sprayed again to the heater (22). An absorption heat pump cycle is formed by such circulation of the refrigerant and the absorption liquid, and the fluid to be heated having a higher temperature than the low temperature fluid used as the heat source is pipe (30) ′.
It is taken out from.

It should be noted that FIG. 2 shows that in this machine, water is used as a refrigerant, lithium bromide aqueous solution is used as an absorbing liquid, and waste steam at about 70 ° C. is supplied as a heat source to the generator (1) and the low temperature evaporator (3), The inlet and outlet temperatures of the cooling water passing through the condenser (2) are about 32 ° C and about 26 ° C, respectively.
It is an example of a Dühring diagram when operated at ℃. In this operation, the warm water flowing into the heated unit (26) at about 119 ° C is heated to about 5 ° C, and the pipe (30) '
Hot water of about 124 ° C. is taken out from.

Then, an operation example of the control device of the present invention in the case where the temperature or flow rate of the waste steam or cooling water supplied to the machine changes and the operating state of the machine changes will be described.

For example, when the temperature of the cooling water flowing into the cooler (23) of the condenser (2) increases, the condensation amount of the refrigerant in the condenser (2) decreases, and the internal pressure of the condenser (2) rises. Condenser and hot evaporator
Although the pressure difference between (5) becomes small, the discharge force of the first pump (9) is almost constant.
Since the amount of the refrigerant liquid sent from (2) to the high temperature evaporator (5) increases, the liquid surface of the refrigerant liquid reservoir (31) of the condenser (2) starts to descend. When the liquid level starts to drop, the opening of the first control valve (V ₁ ) is reduced by the signal from the first liquid level controller (C ₁ ). Then, the liquid level of the refrigerant liquid reservoir (31) is returned to the same level as that before the cooling water temperature became high, and the flow rate of the refrigerant liquid sent from the condenser (2) to the high temperature evaporator (5) is the condenser ( The amount of refrigerant condensed in 2) is almost the same and the operation becomes stable. Further, for example, when the temperature of the waste steam flowing into the heat supply device (24) of the low temperature evaporator (3) rises, the amount of refrigerant vapor evaporated in the low temperature evaporator (3) increases and the heat in the absorber (4) increases. The amount of heat exchanged by the exchanger (25) also increases, and the amount of refrigerant evaporated in the high temperature evaporator (5) increases. Moreover, the pressure difference between the low temperature evaporator (3) and the high temperature evaporator (5) is small, whereas the discharge force of the second pump (10) is almost constant. Since the amount of the refrigerant liquid sent from (5) to the low temperature evaporator (3) is reduced, the liquid level of the refrigerant liquid reservoir (32) of the high temperature evaporator (5) begins to rise. When the liquid level starts rising, the opening of the second control valve (V ₂ ) is increased by the signal from the second liquid level controller (C ₂ ). Then, the liquid level of the refrigerant liquid reservoir (32) is returned to the same level as that before the temperature of the waste steam became high,
The flow rate of the refrigerant liquid sent from the high temperature evaporator (5) to the low temperature evaporator (3) is the amount of refrigerant flowing from the condenser (2) into the high temperature evaporator (5) and the amount of refrigerant evaporated in the high temperature evaporator (5). The difference is almost the same as the difference and the operation becomes stable. On the contrary, when the temperature of the waste steam flowing into the heat supply device (24) becomes low, the liquid level of the refrigerant sump (32) begins to descend, so the second liquid level controller (C ₂ ) The opening degree of the second control valve (V ₂ ) is increased. Then, the flow rate of the refrigerant liquid sent from the high temperature evaporator (5) to the low temperature evaporator (3) is evaporated in the high temperature evaporator (5) with the amount of the refrigerant flowing from the condenser (2) into the high temperature evaporator (5). The difference is almost the same as the amount of the refrigerant, and the operation is stable.

In this way, in this machine equipped with the control device of the present invention, even when the temperature of waste steam or cooling water supplied to this machine fluctuates, the liquid level of the refrigerant liquid reservoirs (31), (32) Since the flow rate of the refrigerant liquid is controlled so as to be almost constant, the fluctuation of the evaporation amount of the refrigerant in the high temperature evaporator (5) becomes small, and it is obtained from the heated device (26) of the high temperature absorber (6). The temperature of the fluid to be heated does not fluctuate as much as the conventional absorption heat pump of this type, which the control device of the present invention does not have.

(F) Effect of the invention As described above, the present invention, in this type of absorption heat pump, adjusts the flow rate of the refrigerant liquid from the condenser to the high temperature evaporator in accordance with the amount of the refrigerant liquid in the condenser, and evaporates the high temperature. By adjusting the flow rate of the refrigerant liquid from the evaporator to the low temperature evaporator according to the amount of the refrigerant liquid in the high temperature evaporator, the temperature or amount of the cooling water supplied to the absorption heat pump, the waste steam for the heat source and other low temperature fluids. Since the amount of the refrigerant liquid in the high-temperature evaporator is kept almost constant even when fluctuates, compared with the conventional absorption heat pump of this type, the amount of the refrigerant liquid returned to the high-temperature evaporator by the pump is Fluctuation becomes small. Therefore, the fluctuation of the evaporation amount of the refrigerant in the high temperature evaporator is small, the refrigerant absorption amount of the absorbing liquid in the high temperature absorber does not fluctuate as much as the conventional absorption heat pump of this type, and the amount of the refrigerant taken out from the absorber is small. The temperature fluctuation of the heating fluid also becomes small.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory view showing an embodiment of a control device of the present invention, and FIG. 2 is a diagram showing an example of a Duhring diagram when the absorption heat pump of this kind shown in FIG. 1 is operated. Is. (1) …… Generator, (2) …… Condenser, (3) …… Low temperature evaporator,
(4) …… Absorber, (5) …… High temperature evaporator, (6) …… High temperature absorber, (7), (8) …… High temperature and low temperature solution heat exchanger, (9), (1
0), (11) …… first, second, third pump, (12) …… pump, (22) …… heater, (23) …… cooler, (24) …… heater, (25) …… Heat exchanger, (26) …… Heating target, (31), (32)
... Refrigerant sump, (C ₁ ), (C ₂ ) ... 1st, 2nd liquid level controller, (V ₁ ), (V ₂ ) ... 1st, 2nd control valve.

Claims (1)

[Claims] 1. A generator driven by the heat of waste vapor or other low temperature fluid, a condenser, a low temperature evaporator for evaporating a refrigerant by the heat of waste vapor or other low temperature fluid, and a refrigerant vapor from the low temperature evaporator as an absorbing liquid. An absorber that heats the refrigerant liquid in the heat exchanger built into the container by the heat generated when absorbing, a high-temperature evaporator that evaporates the refrigerant liquid that has been heated in the heat exchanger of the absorber inside the container, The heat generated when the absorption liquid absorbs the refrigerant vapor from the high-temperature evaporator, the absorber that raises the temperature of the hot water and other heated fluid inside the heated equipment built in the vessel, and the solution heat exchanger are connected by piping. In the absorption heat pump consisting of, a control valve is provided on the discharge side of the pump that sends the refrigerant liquid from the condenser to the high temperature evaporator, and the opening of this control valve is controlled according to the amount of the refrigerant liquid in the condenser and A control valve is installed on the discharge side of the pump that sends the refrigerant liquid from the low temperature evaporator to the low temperature evaporator. That the opening of the control valves so as to control in accordance with the refrigerant liquid amount in the high temperature evaporator Te control device of the absorption heat pump according to claim.