JP3075944B2 - Absorption chiller / heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller / heater, and more particularly to an absorption chiller / heater in which a cooling water circulation path is formed by connecting an absorber, a condenser and a cooling tower with piping.

[0002]

2. Description of the Related Art For example, Japanese Unexamined Patent Publication No. Hei 5-248723 discloses an auxiliary pipe connecting the downstream side of a cooling water circulating pump and a connecting pipe from a condenser to a cooling tower. The switching control means is temporarily opened when switching from the heating operation mode to the cooling operation mode, and the low-temperature cooling water from the cooling tower flows to the connecting pipe via the auxiliary pipe, and the high-temperature cooling from the condenser is performed. Mix with water to lower temperature. After a certain period of time, after the high temperature state of the cooling water is eliminated, an absorption-type cold / hot water unit is disclosed in which the opening / closing control means is closed to shift to a normal cooling operation. Therefore, when switching from the heating operation mode to the cooling operation mode, high-temperature cooling water does not flow directly to the cooling unit, and damage to the cooling unit can be avoided.

[0003]

In the above prior art,
Regardless of the temperature of the cooling water flowing out of the condenser at the time of switching from the heating operation mode to the cooling operation mode, the open / close control means is opened, and a certain amount of the cooling water flowing out of the cooling unit flows through the auxiliary pipe for a certain time, For this reason, for example, even when the time of the heating operation mode is short and the temperature of the cooling water of the absorber and the condenser is not high, the amount of the cooling water flowing to the absorber and the condenser for a certain period of time decreases, and The refrigerant absorption capacity of the condenser and the condenser vapor condensation capacity of the condenser do not increase, and as a result,
There is a problem that switching to the cooling operation mode is delayed.

When the opening / closing control means is closed after the lapse of the predetermined time, the low-temperature cooling water discharged from the cooling water circulation pump rapidly flows to the absorber and the condenser, and the capacity of the absorber and the condenser is reduced. It recovers rapidly and the refrigeration capacity also increases rapidly. For this reason, the temperature of the chilled water flowing out of the evaporator also suddenly drops, causing problems such as the chilled water outlet temperature falling below the set temperature and hunting of the chilled water outlet temperature.

It is an object of the present invention to smoothly and quickly switch from a heating operation mode (hot water supply operation) to a cooling operation mode (cold water supply operation) while avoiding damage to the cooling tower.

[0006]

In order to solve the above-mentioned problems, the present invention is directed to a method of circulating a refrigerant and an absorbing liquid by connecting a regenerator, a condenser, an evaporator, an absorber and the like with piping. A cooling water supply operation to supply cooling water from the evaporator and a refrigerant water flow from the regenerator to the evaporator by forming a cooling water circulation path by connecting piping to the absorber, condenser, cooling tower and cooling water pump Chilled water heater that switches between hot water supply operation and hot water supply operation that supplies hot water from the evaporator, is connected via a control valve between the downstream side of the cooling water pump and the cooling water circulation path from the condenser to the cooling tower A bypass pipe that bypasses the absorber and the condenser, a temperature detector that detects the temperature of the cooling water flowing into the cooling tower, and a temperature detected by the temperature detector after switching from the hot water supply operation to the cold water supply operation. Flows into the bypass pipe as Flow rate of 却水 is intended to provide an absorbent chiller that includes a control device for controlling the opening of the control valve so as to increase.

According to a second aspect of the present invention, a regenerator, a condenser, an evaporator, an absorber, and the like are connected by piping to form a circulation path for the refrigerant and the absorbing liquid, and the absorber, the condenser, the cooling tower, and the cooling device are formed. A water pump is sequentially connected to form a cooling water circulation path, and the operation is switched between a cold water supply operation that supplies cold water from the evaporator and a hot water supply operation that sends refrigerant vapor from the regenerator to the evaporator and supplies hot water from the evaporator. In the absorption chiller / heater to be performed, a bypass pipe that is connected through a control valve between a downstream side of the cooling water pump and a cooling water circulation path from the condenser to the cooling tower, and bypasses the absorber and the condenser, A temperature detector for detecting the temperature of the cooling water flowing into the cooling tower, and the following equation mxCp × T3 = until the detected temperature of the temperature detector drops to the set temperature after switching from the hot water supply operation to the cold water supply operation. m1 × Cp × T1 + (m−m1) × C
m = 1 in p × T2, T1 = upper limit value of cooling water absorber inlet side temperature,
T2 = upper limit value of the outlet temperature of the condenser, T3 = upper limit value of the cooling water inlet side temperature of the cooling water, and Cp = control the ratio of the cooling water flowing into the bypass pipe obtained by inputting the specific heat of the cooling water to m1. A control device for controlling the opening of the valve on the side of the bypass pipe is provided.

Further, according to a third aspect of the present invention, a regenerator, a condenser, an evaporator, an absorber and the like are connected by piping to form a circulation path for the refrigerant and the absorbing liquid, and the absorber, the condenser, the cooling tower, and the cooling device are formed. A water pump is sequentially connected to form a cooling water circulation path, and the operation is switched between a cold water supply operation that supplies cold water from the evaporator and a hot water supply operation that sends refrigerant vapor from the regenerator to the evaporator and supplies hot water from the evaporator. In the absorption chiller / heater to be performed, a bypass pipe that is connected through a control valve between a downstream side of the cooling water pump and a cooling water circulation path from the condenser to the cooling tower, and bypasses the absorber and the condenser, A cooling water inlet temperature detector for detecting the cooling water temperature on the inlet side of the absorber, a cooling water outlet temperature detector for detecting the cooling water temperature on the outlet side of the condenser, a cooling water outlet temperature detector, and a cooling water inlet Supplying hot water by inputting a temperature signal from a temperature detector After switching to the cold water supply operation from a converter,
The following formula: mx Cp x T3 = m1 x Cp x T1 + (m-m1) x C
m = 1, T1 = detected temperature of cooling water inlet temperature detector, p × T2, T
2 = detected temperature of the cooling water outlet temperature detector, T3 = upper limit value of the temperature of the cooling water at the inlet of the cooling tower, and Cp = ratio m1 of the cooling water flowing to the bypass pipe obtained by inputting the specific heat of the cooling water. A control device for controlling an opening degree of a control valve on a bypass pipe side is provided.

According to a fourth aspect of the present invention, a regenerator, a condenser, an evaporator, an absorber, and the like are connected by piping to form a circulation path for the refrigerant and the absorbing liquid, and the absorber, the condenser, the cooling tower, and the cooling device are provided. A water pump is sequentially connected to form a cooling water circulation path, and the operation is switched between a cold water supply operation that supplies cold water from the evaporator and a hot water supply operation that sends refrigerant vapor from the regenerator to the evaporator and supplies hot water from the evaporator. In the absorption chiller / heater to be performed, a bypass pipe that is connected through a control valve between a downstream side of the cooling water pump and a cooling water circulation path from the condenser to the cooling tower, and bypasses the absorber and the condenser, A temperature detector that detects the temperature of the cooling water flowing into the cooling tower, and a flow rate of the cooling water flowing through the bypass pipe as the detected temperature of the temperature detector increases after switching from the hot water supply operation to the cold water supply operation. Control valve opening to increase It is to provide an absorbent chiller having a control device for continuously outputting driving signals to the cooling tower as well as.

[0010]

According to the first aspect of the present invention, when switching from the hot water supply operation to the cold water supply operation, the control device controls the opening degree of the valve based on the cooling water outlet temperature detected by the temperature detector,
The high-temperature cooling water from the absorption chiller / heater and the low-temperature cooling water from the bypass pipe are mixed appropriately to the cooling tower, the temperature drops and returns, and members such as heat exchangers that constitute the cooling tower are damaged. This can prevent the cooling tower from malfunctioning, lowering the cooling capacity, etc., and improve the safety of the cooling water circulation circuit.

According to the second aspect of the present invention, the opening degree of the valve on the bypass pipe side at the time of switching from the hot water supply operation to the cold water supply operation is determined in advance by the upper limit value T of the cooling water absorber inlet side temperature.
1. The upper limit value T2 of the outlet temperature of the condenser, the upper limit value of the cooling water on the inlet side of the cooling tower, that is, the upper limit value T3 of the cooling water outlet temperature, the specific heat Cp of the cooling water, and the total cooling water flow rate m = 1. When the calculated actual absorption chiller / heater is operated, when the hot water supply operation is switched to the chilled water supply operation, the opening of the valve on the bypass pipe side is controlled to the previously calculated opening, and as a result, the cooling water When the temperature at the inlet side of the absorber has risen to near the upper limit value T1, when the cooling water temperature at the outlet side of the condenser has risen to near the upper limit value T2, or when the temperature of the cooling water at the inlet side of the absorber has increased. And the cooling water temperature on the outlet side of the condenser is the upper limit value T1,
Even when the temperature rises to near T2, the cooling water outlet temperature is reliably suppressed to be lower than the upper limit T3, so that the cooling tower can be easily prevented from being damaged by the high-temperature cooling water.

According to the third aspect of the present invention, when the operation is switched from the hot water supply operation to the cold water supply operation, the opening degree of the valve on the bypass pipe side is determined by the cooling water absorber inlet side temperature t1, the condenser outlet side. It is calculated based on the side temperature t2, the upper limit value of the cooling water on the inlet side of the cooling tower, that is, the upper limit value T3 of the cooling water outlet temperature, the specific heat Cp of the cooling water, and the total cooling water flow rate m = 1. Then, when switching from the hot water supply operation to the cold water supply operation during the actual operation of the absorption chiller / heater, the opening of the valve on the bypass pipe side is controlled to the calculated opening. Therefore, the higher the temperature of the cooling water on the inlet side of the cooling water or the higher the cooling water temperature on the outlet side of the condenser, the greater the degree of opening of the valve on the bypass pipe side of the valve by the control device. Thus, the opening of the valve can be controlled, the cooling water outlet temperature is reliably suppressed to be lower than the upper limit T3, and the cooling tower can be easily prevented from being damaged by the high-temperature cooling water.

Further, according to the present invention, when the operation is switched from the hot water supply operation to the cold water supply operation, the control device controls the opening degree of the valve based on the cooling water outlet temperature detected by the temperature detector. In addition, it is possible to prevent high-temperature cooling water from returning to the cooling tower, and it is possible to prevent members such as a heat exchanger constituting the cooling tower from being damaged. Also, since the cooling tower starts operation immediately after switching from the hot water supply operation to the cold water supply operation, the cooling water returned to the cooling tower is radiated and cooled immediately after the switching, and flows to the absorber and the condenser, respectively. Temperature can be promoted.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. A shown in the figure is an absorption chiller / heater,
For example, water (H2 O) is used as a refrigerant and a lithium bromide (LiBr) solution is used as an absorbing solution (solution). In the figure, 1 is a regenerator provided with a gas burner 1B, 2 is a condenser,
Reference numeral 3 denotes a lower body in which the evaporator 4 and the absorber 5 are housed, 6 denotes a cooling tower, 7 denotes a heat exchanger, 8 to 11 denotes an absorbent pipe, 12 denotes an absorbent pump, and 13 denotes a regenerator 1 and a heat exchanger 7. , An absorption liquid pipe that branches off from the middle of the absorption liquid pipe 10 to the absorber 5 of the lower body 3, 14 is a first open / close valve provided in the middle of the absorption liquid pipe 13, and 15 and 16 are refrigerants. A pipe, 17 is a refrigerant circulation pipe, 18 is a refrigerant pump, 20 is a refrigerant vapor pipe that branches off from the middle of the refrigerant pipe 15 and reaches the gas phase portion of the absorber 5 of the lower body 3, and 21 is a part of the refrigerant vapor pipe 20. It is a second on-off valve provided.

Reference numerals 22 to 24 denote absorber heat exchangers 25 on the way.
And the condenser heat exchanger 26 is connected to the cooling water pipes 22, 23 and 24. The cooling water is supplied from the cooling tower 6 to the absorber heat exchanger 25 and the condenser heat exchanger 2.
The cooling tower 6 is connected so as to flow sequentially through the cooling tower 6.
A cooling water pump 27 and a third on-off valve 28 are provided in the cooling water pipe 22. A fourth opening / closing valve 29 is provided in the cooling water pipe 24.
Reference numeral 30 denotes a bypass pipe branched from the downstream side of the coolant pump 27 of the cooling water pipe 22 and connected to the downstream side of the fourth opening / closing valve 29 via a three-way valve 31. The bypass pipe 30 includes an absorber heat exchanger 25 and a condenser heat exchanger. They are connected by a bypass 26.

Reference numeral 32 denotes a control unit for the absorption type water heater, and reference numeral 33 denotes a first temperature detector provided on the cooling tower 6 side of the three-way valve 31 of the cooling water pipe 24. The control device 32 is constituted by, for example, a microcomputer. The relationship as shown in FIG. 2 with the side opening (cooling water pipe side opening) is stored in advance. Then, at the time of switching from the hot water supply operation to the cold water supply operation, the control device 32 outputs an opening signal to the three-way valve 31 based on the relationship in FIG. The control device 32
Outputs a close signal to the first and second on-off valves 14 and 21 during the cold water supply operation, and outputs an open signal during the hot water supply operation. Further, the control device 32 controls the third and fourth on-off valves 28 and 29.
An open signal is output during cold water supply operation, and a close signal is output during hot water supply operation. Further, the control device 32 controls the cooling water pump 2
During the operation of 7, an operation signal is output to the fan motor 6M that drives the blower fan 6F of the cooling tower 6.

Reference numeral 35 denotes a cold / hot water pipe connected to the evaporator 3, reference numeral 36 denotes an evaporator heat exchanger, and reference numeral 37 denotes a cold / hot water pump. Reference numeral 38 denotes a cold / hot water temperature detector which is provided on the outflow side of the evaporator 3 of the cold / hot water pipe 35 and detects the outlet temperature of the cold / hot water. The cold water supply operation and the hot water supply First, second, third, fourth based on driving
A program for controlling the opening and closing of the on-off valve, a program for controlling the heating amount of the burner 1B based on the temperature of the cold / hot water outlet, and the like are stored in advance.

Hereinafter, the operation of the absorption chiller / heater configured as described above during operation will be described. During cold water supply operation,
The control device 32 outputs a close signal to the first and second on-off valves 14 and 21 and outputs a close signal to the third and fourth on-off valves 28 and 29. Further, the control device 32 outputs a combustion signal to the burner 1B, and the burner 1B burns. Then, the absorbent having a low concentration (hereinafter referred to as a diluted absorbent) is heated in the regenerator 1, and the refrigerant separates from the diluted absorbent and evaporates. The evaporated refrigerant flows to the condenser 2. The refrigerant vapor flowing from the regenerator 1 to the condenser 3 exchanges heat with the cooling water flowing through the condenser heat exchanger 26 to be condensed and liquefied, and flows to the evaporator 3 via the refrigerant pipe 16. Then, the refrigerant liquid evaporates by exchanging heat with the cold water in the evaporator heat exchanger 35, and the cold water is cooled by the heat of vaporization and supplied to the load. The refrigerant evaporated in the evaporator 3 flows to the absorber 5 and is sprayed with a thick absorbent (hereinafter, referred to as a thick liquid).
Is absorbed by

The diluted absorption liquid whose concentration has been reduced by absorbing the refrigerant in the absorber 5 is heated by the operation of the absorption liquid pump 12 through the heat exchanger 7 and sent to the regenerator 1. The diluted absorbent flowing into the regenerator 1 is heated by the burner 1B,
The refrigerant separates and evaporates, and the concentrated liquid having a higher concentration drops in temperature through the heat exchanger 7, drops in temperature and flows to the absorber 5,
Sprayed.

When the absorption chiller / heater is operating as described above, the controller 32 inputs a chilled water outlet temperature signal from the chilled / hot water temperature detector 38, and based on this signal, the burner 1
The amount of fuel supplied to B is adjusted, and the amount of heating of burner 1B is controlled. Further, the control device 32 includes a first temperature detector 33.
2 stored in the storage device 34 as shown in FIG.
Is output to the three-way valve 31 based on the relationship. The detected temperature of the first temperature detector 33 is, for example, 40 ° C.
In the following cases, the opening of the three-way valve 31 on the bypass pipe 30 side is controlled to 0%, and the opening of the cooling water pipe 24 is controlled to 100%.

When the cooling water supply operation is performed as described above, and the season shifts from the summer season in which the cooling operation is performed, for example, in the fall or winter, when the heating operation by the hot water supply operation is required, the administrator operates the controller 32. Changeover switch 32
Operate S. By operating the changeover switch 32S, the control device 32 operates to output an open signal to the first and second on-off valves 14 and 21, output a close signal to the third and fourth on-off valves 28 and 29, and Output the operation stop signal.

By the output of the signal, the first and second on-off valves 14 and 21 are opened, and the refrigerant vapor generated in the regenerator 1 flows through the refrigerant pipe 15 and the refrigerant vapor pipe 20 to the absorber side of the lower body 3. Further, the concentrated liquid having a higher concentration due to separation of the refrigerant in the regenerator 1 flows to the evaporator 4, and flows from the regenerator 1 to the absorber 5 via the absorbent pipes 10 and 13. Further, the third and fourth on-off valves 28 and 29 are closed, the cooling tower 6 stops operating,
The circulation of the cooling water to the absorber heat exchanger 25 and the condenser heat exchanger 26 is stopped.

When the refrigerant vapor flows into the evaporator 4 as described above, the cold water flowing through the evaporator heat exchanger 36 is heated, the temperature rises to become hot water, and the hot water is supplied to the load to switch to the hot water supply operation. , Heating operation is performed. Then, the control device 32 inputs a signal of the hot water outlet temperature from the cold / hot water temperature detector 38, and based on this signal, the fuel supply amount to the burner 1B is adjusted, and the heating amount of the burner 1B is controlled.

The hot water supply operation is performed as described above. For example, when heating operation is performed in an office or a store by supplying hot water, the indoor temperature of the office or the indoor temperature of the store increases and the heating operation is performed. When switching from the heating operation to the cooling operation, that is, when switching to the cooling operation, that is, when switching to the cooling water supply operation, the control device 32 operates, and
A closing signal is output to the second on-off valves 14 and 21, an open signal is output to the third and fourth on-off valves 28 and 29, and an operation signal is output to the fan motor 6 M of the cooling tower 6 and the cooling water pump 27.

The first and second on-off valves 1 are operated according to the closing signal.
4 and 21 are closed, the third and fourth on-off valves 28 and 29 are open,
In addition, the cooling tower 6 and the cooling water pump 27 start operating,
The cold water supply operation as described above starts. The control device 3
2 receives a temperature signal from the first temperature detector 33 and outputs an opening signal based on the relationship of FIG. 2 stored in the storage device 34 to the three-way valve 31. When switching from the hot water supply operation to the cold water supply operation, the control device 32 outputs an open signal to both the bypass pipe side of the three-way valve 31 and the cooling water pipe 24 side. For this reason, the cooling water remaining in the absorber heat exchanger 25 and the condenser heat exchanger 26 and having increased in temperature during the hot water supply operation and being increased is pushed out by the cooling water discharged from the cooling water pump 27. It is. A part of the low-temperature cooling water stored in the cooling tower 6 flows through the bypass pipe 30. Then, the absorber heat exchanger 25 and the condenser heat exchanger 2
6, that is, the high-temperature cooling water flowing from the absorption chiller / hot-water machine main body and the low-temperature cooling water flowing through the bypass pipe 30 are combined by the three-way valve 31 and flow to the cooling tower 6. In the cooling tower 6, the inflowing cooling water is cooled, the temperature of the cooling water drops, and the cooling water is discharged from the cooling pump 27.

The first temperature detector 33 detects the temperature of the cooling water flowing to the cooling tower 6, and the control device 32 controls the opening of the three-way valve 31 based on the detected temperature as described above. Then, after switching from the hot water supply operation to the cold water supply operation, when the temperature of the cooling water flowing from the absorption chiller / hot water heater main body is high and the temperature of the cooling water flowing to the cooling tower 6 is high, the relationship shown in FIG. The control device 32 controls the bypass pipe 3 of the three-way valve 31.
Control is performed so that the opening degree on the 0 side is large and the opening degree on the cooling water pipe 24 side is small. For example, when the temperature detected by the first temperature detector 33, that is, the temperature of the cooling water flowing to the cooling tower 6 (hereinafter, referred to as a cooling water outlet temperature) is 50 ° C. or more, the control device 32 controls the bypass of the three-way valve 31. The opening on the pipe 30 side is controlled to, for example, 100%, and the opening on the cooling water pipe 24 side is controlled to 0%. Therefore, all of the cooling water discharged from the cooling water pump 27 flows to the bypass pipe 30. Here, when the cooling water outlet temperature is 50 ° C. or more, for example, the opening of the three-way valve 31 on the side of the bypass pipe 30 is controlled to 95%, the opening of the cooling water pipe 24 is controlled to 55%, and the cooling water is gradually reduced. Absorber heat exchanger 2
5 and the condenser heat exchanger 26 side, the cooling water outlet temperature decreases little by little, it is possible to prevent a sudden change of the cooling water outlet temperature, and the opening degree of each side of the three-way valve 31 is sharp. Fluctuations can be avoided.

Immediately after the switching, time elapses and the heat exchanger 25 and the condenser heat exchanger 2 are operated by natural heat radiation or the like.
When the cooling water temperature of the cooling water outlet 6 gradually decreases and the cooling water outlet temperature gradually decreases, the control device 32 reduces the opening degree of the three-way valve 31 on the bypass pipe side as shown in FIG. Of the three-way valve 31 is controlled so as to increase. As a result, the amount of cooling water flowing through the absorber heat exchanger 25 and the condenser heat exchanger 26 in the cooling water discharged from the cooling water pump 27 increases, and the cooling water flowing through the bypass pipe 30 is inversely proportional to this increase. The amount of is reduced. When the cooling water outlet temperature becomes, for example, 40 ° C. or less, the control device 32 controls the opening of the three-way valve 31 on the cooling water pipe 4 side to 100% and the opening on the bypass pipe 30 side to 0%. Then, the whole amount of the cooling water discharged from the cooling water pump 27 flows to the absorber heat exchanger 25 and the condenser heat exchanger 26, and the cold water is supplied as in the above-described cold water supply operation.

According to the first embodiment of the present invention, when the operation is switched from the hot water supply operation to the cold water supply operation, the control device 32 determines the temperature of the cooling water outlet detected by the first temperature detector 33. The opening of the three-way valve 31 is controlled, so that high-temperature cooling water can be prevented from returning to the cooling tower 6, and a member such as a heat exchanger constituting the cooling tower 6 can be prevented from being damaged. Of the cooling water circulation circuit can be prevented, and the safety of the cooling water circulation circuit can be improved.

Further, the control device 32 controls the first temperature detector 3
3 controls the opening degree of the three-way valve 31 based on the detected cooling water outlet temperature, so that the control device 32 is controlled based on the cooling water temperatures of the absorber heat exchanger 25 and the condenser heat exchanger 26 immediately after the operation switching. When the temperature of the cooling water from the absorber heat exchanger 25 and the condenser heat exchanger 26 or the cooling tower 6 is relatively low, the entire amount of the cooling water is absorbed in a short time. Since the heat flows into the heat exchanger 25 and the condenser heat exchanger 26, the operation is switched from the hot water supply operation to the cold water supply operation in a short time. Further, since the cooling tower 6 starts operating immediately after switching from the hot water supply operation to the cold water supply operation, the cooling water returned to the cooling tower 6 is radiated and cooled immediately after the switching, so that the absorber heat exchanger 25 and The heat flows to the condenser heat exchanger 26, and the temperature of each heat exchanger can be reduced.

Further, immediately after switching from the hot water supply operation to the cold water supply operation, the control device 32
3, the opening degree of the three-way valve 31 is controlled based on the detected cooling water outlet temperature, so that the cooling water whose temperature has decreased after the operation is switched is completely absorbed by the absorber heat exchanger 25 and the condenser heat exchanger 26.
Can be prevented from flowing rapidly. As a result, the absorber 5
The rapid change in the absorption capacity of the condenser 2 and the condensation capacity of the condenser 2 can be avoided, and the operation can be stabilized by preventing hunting of the chilled water outlet temperature after the operation is switched.

Also, when the operation is switched from the hot water supply operation to the cold water supply operation, even when the cooling water outlet temperature is high, the whole amount of the cooling water discharged from the cooling water pump 27 is not supplied to the bypass pipe 30 but the cooling water is supplied. When flowing into the absorber heat exchanger 25 and the condenser heat exchanger 26 little by little, the hunting of the opening and closing of the three-way valve 33 that occurs when the whole amount of the cooling water flows into the bypass pipe 30 when the cooling water outlet temperature is high. That is, when the opening degree of the three-way valve 31 on the bypass pipe 30 side is set to 100%, the cooling water pipe 24 side is set to 0%, and the entire amount of the cooling water flows through the bypass pipe 30; The opening degree is made smaller than 100%, and it is possible to avoid the repetition in a short time of opening the cooling water pipe 24 and opening a part of the cooling water to the absorption chiller / heater main body side. Prevent failure Te, it is possible to simplify the maintenance work.

Hereinafter, a second embodiment of the present invention will be described with reference to FIG. Note that, in FIG. 3, the components having the same reference numerals as those in FIG. 1 are the same, and detailed description thereof will be omitted. Instead of the relationship between the cooling water outlet temperature and the opening of the three-way valve 31 on the bypass pipe side and the opening of the three-way valve 31 on the cooling water pipe side of FIG. Valve 31
Is controlled to a ratio m1 of the cooling water flow rate on the bypass pipe 30 side to the total cooling water flow rate calculated based on the following equation 1, and the cooling water pipe 24 of the three-way valve 31
A program is stored for controlling the opening on the side to 1 to the opening obtained by subtracting the opening on the bypass pipe 30 from 1.

M × Cp × T3 = m1 × Cp × T1 + (m−m1) × Cp × T2 Formula 1 In the above formula 1, m = total cooling water flow rate = 1, T1 =
Upper limit of cooling water absorber inlet side temperature, T2 = upper limit of condenser outlet side temperature, T3 = upper limit of cooling water cooling tower inlet side, ie upper limit of cooling water outlet temperature, Cp = cooling water Specific heat. Here, the upper limit value T1 of the cooling water absorber inlet side temperature
Varies in advance according to the climate of the region where the absorption chiller / heater is installed, and is set, for example, to 32 ° C., and the upper limit T2 of the outlet temperature of the condenser is determined by the operating state of the absorption chiller / heater during the hot water supply operation. Is set in advance to, for example, 80 ° C., and the upper limit T3 of the cooling water outlet temperature is set in advance to, for example, 45 ° C., which is lower than the temperature at which damage to the cooling tower 6 can be prevented. And
By substituting the upper limits T1, T2, and T3 into Equation 1, the opening degree m1 = 0.
73 is calculated.

The cooling water pipe 24 is provided with a first temperature detector 33 for detecting the temperature of the cooling water outlet, similarly to the first embodiment, and is connected to the control device 32. The storage device 34 of the control device 32 includes a first temperature detector 33
A program for controlling the three-way valve 31 based on the detected coolant outlet temperature is stored. The controller 32 outputs a signal to the three-way valve 31 when the temperature detected by the first temperature detector 33, that is, the cooling water outlet temperature drops to a preset lower limit temperature, for example, 40 ° C. The opening of the valve 31 on the cooling water pipe 4 side is controlled to 100%, and the opening of the valve 31 on the bypass pipe 30 side is controlled to 0%, so that the entire amount of cooling water discharged from the cooling water pump 27 is absorbed by the absorber heat exchanger 25 and condensed water. Heat exchanger 2
6 and the cold water is supplied as in the cold water supply operation.

For example, at the time of trial operation and operation of the absorption chiller / heater configured as described above, the cold water supply operation and the hot water supply operation are performed in the same manner as the operation shown in the first embodiment. Then, when switching from the hot water supply operation to the cold water supply operation of the absorption refrigerator, the control device 32 outputs an opening signal to the three-way valve 31. For example, when the absorption refrigerator performs the hot water supply operation in autumn, winter, or spring, the indoor temperature rises due to congestion of the store, and the operation switches from the hot water supply operation to the cold water supply operation.

At the time of switching to the cooling water operation, the control device 32 operates to output a signal to the three-way valve 31, so that the opening degree on the bypass pipe 30 side is 73% and the opening degree on the cooling water pipe side is 27%. Controlled. For this reason, the absorber heat exchanger 25 and the condenser heat exchanger 2 whose temperature has increased during the cold water supply operation, that is, the heating operation,
The hot water of No. 6 is mixed with the cold water from the bypass pipe 30 by the three-way valve 31, and the temperature of the hot water drops to return to the cooling tower 6. A part of the cold water discharged from the cooling water pump 27 is supplied to the absorber heat exchanger 25.
Then, the temperature of the hot water flowing to the condenser heat exchanger 26 and staying therein gradually decreases. The operation of the cooling tower 6 is started immediately after the switching.

As time elapses, the cooling water outlet temperature gradually decreases, and when the temperature detected by the first temperature detector 33 decreases to the lower limit temperature, the control device 32 operates to output a signal to the three-way valve 31. I do. For this reason, the opening of the three-way valve 31 on the side of the cooling water pipe 4 becomes 100%, and the opening of the three-way valve 31 on the side of the bypass pipe 30 becomes 0%, and the entire amount of the cooling water discharged from the cooling water pump 27 becomes the absorber heat exchanger. 25 and the condenser heat exchanger 26, and chilled water is supplied from the absorption chiller / heater in the same manner as in the normal chilled water supply operation.

Similarly, when switching from the hot water supply operation to the cold water supply operation, the opening of the three-way valve 33 is controlled in the same manner as described above. According to the second embodiment, the degree of opening of the three-way valve 31 on the bypass pipe 30 side at the time of switching from the hot water supply operation to the cold water supply operation is determined in advance by the equation (1). The upper limit value T1, the upper limit value T2 of the outlet temperature of the condenser, the upper limit value of the cooling water on the inlet side of the cooling tower, that is, the upper limit value T3 of the cooling water outlet temperature, the specific heat Cp of the cooling water, and the total cooling water flow rate m = 1. It is calculated by substituting. Then, at the time of actual operation of the absorption chiller / heater, at the time of switching from the hot water supply operation to the cold water supply operation, the opening of the three-way valve 31 on the bypass pipe 30 side is controlled to the previously calculated opening. As a result, when the temperature of the cooling water on the inflow side of the absorber has risen to near the upper limit value T1, when the temperature of the cooling water on the outflow side of the condenser has risen to near the upper limit value T2, or when the cooling water has been absorbed. The temperature on the inlet side of the condenser and the temperature of the cooling water on the outlet side of the condenser are upper limit values T1, T2.
Even when the temperature rises to near, the cooling water outlet temperature is surely suppressed to be lower than the upper limit value T3, so that the cooling tower 6 can be easily prevented from being damaged by the high-temperature cooling water. In addition, it is possible to prevent a failure of the cooling tower 6, a decrease in cooling capacity, and the like, and to improve safety of the cooling water circulation circuit.

Further, the control device 32 controls the first temperature detector 3
When the cooling water outlet temperature detected by the cooling water outlet 3 drops to the lower limit temperature, it operates and outputs a signal to the three-way valve 31. The opening of the three-way valve 31 on the cooling water pipe 4 side is set to 100%, and the opening on the bypass pipe 30 side. Becomes 0%, and the entire amount of the cooling water discharged from the cooling water pump 27 flows to the absorber heat exchanger 25 and the condenser heat exchanger 26, so that the normal cooling water supply operation can be switched in a short time.

Hereinafter, a third embodiment of the present invention will be described with reference to FIG. Note that, in FIG. 4, the components having the same reference numerals as those in FIGS. 1 and 3 are the same, and the detailed description thereof will be omitted. Instead of the relationship between the cooling water outlet temperature and the opening of the three-way valve 31 on the bypass pipe side and the opening of the three-way valve 31 on the cooling water pipe side of FIG. The opening degree of the valve 31 on the bypass pipe 30 side is controlled to the ratio m1 of the cooling water flow rate on the bypass pipe 30 side to the total cooling water flow rate calculated based on the following equation, and the three-way valve 31 on the cooling water pipe 24 side is controlled. A program for controlling the opening to an opening obtained by subtracting the opening on the bypass pipe 30 side from 1 is stored.

M × Cp × T3 = m1 × Cp × t1 + (m−m1) × Cp × t2 Equation 2 In the above Equation 2, m is the total cooling water flow rate = 1,
t1 = temperature at the inlet of the cooling water into the absorber, t2 = temperature at the outlet of the condenser, T3 = upper limit of the cooling tower inlet side temperature, that is, upper limit of the cooling water outlet temperature, and Cp = specific heat of the cooling water. .
Here, the upper limit value T3 of the cooling water outlet temperature is set in advance to, for example, 45 ° C., which is lower than the temperature at which the cooling tower 6 can be prevented from being damaged, and is stored in the storage device.

In the absorption chiller / heater according to the third embodiment, a second temperature detector 40 for detecting the temperature of the inflow side of the absorber 5 of the cooling water is provided in the cooling water pipe 22 to condense the cooling water. Temperature detector 41 for detecting the temperature at the outlet side of the detector 2
Is provided on the condenser side of the three-way valve 31 of the cooling water pipe 24. When the absorption chiller / heater configured as described above is operated, the cold water supply operation and the hot water supply operation are performed as shown in the first embodiment. Then, when switching from the hot water supply operation to the cold water supply operation, the control device 32 outputs an opening signal to the three-way valve 31 so that the cooling water outlet temperature becomes equal to or lower than the upper limit value of 45 ° C. For example, immediately after the switching, the second temperature detector 40
Is 30 ° C. and the coolant outlet side temperature of the cooling water detected by the third temperature detector 41 is 75 ° C., the control device 32 calculates m =
1, Cp = 1, T3 = 45, t1 = 30 and t2 = 70
And m1 = 0.625 (62.5%) is calculated. And. The control device 32 sets the opening on the bypass pipe side of the three-way valve 33 to 63%, which is slightly larger than the calculated opening, and sets the opening on the cooling water pipe side to 100- so that the cooling water outlet temperature becomes equal to or lower than the upper limit value. 63 = 37%.

Thereafter, the temperature at the outlet of the condenser gradually decreases with the passage of time due to heat radiation from the cooling water. Then, the value calculated by the control device 32, that is, the opening m1 of the three-way valve 33 on the bypass pipe side gradually decreases, and the opening degree on the cooling water pipe side gradually increases. For example, the coolant inlet side temperature of the cooling water detected by the second temperature detector 40 is 30 ° C., and the condenser outlet side temperature of the cooling water detected by the third temperature detector 41 is 5 ° C.
At 0 ° C., the control device 32 determines that m = 1,
By substituting Cp = 1, T3 = 45, t1 = 30 and t2 = 50, m1 = 0.250 (25.0%) is calculated. And. The control device 32 sets the opening on the bypass pipe side of the three-way valve 33 to, for example, 26% slightly larger than the calculated opening and sets the opening on the cooling water pipe side to 100% so that the cooling water outlet temperature becomes equal to or lower than the upper limit value. -26 = 74% is controlled.

Further, after a lapse of time, the temperature of the cooling water at the outlet of the condenser becomes 45 ° C. which is equal to the upper limit temperature of the cooling water outlet temperature.
Becomes, the control device 32 calculates m1 = 0,
The opening on the bypass pipe side of the three-way valve 33 is controlled to 0%, and the opening on the cooling water pipe side is controlled to 100%, so that the entire amount of cooling water discharged from the cooling water pump 27 is absorbed by the absorber heat exchanger 25 and the condenser. To the heat exchanger 26. As a result, cold water is supplied from the absorption chiller / heater in the same manner as during the normal cold water supply operation.

According to the third embodiment, the opening degree of the three-way valve 31 on the bypass pipe 30 side when switching from the hot water supply operation to the cold water supply operation is calculated by the equation (2). t1, the outlet temperature t2 of the condenser, the upper limit value of the cooling water on the inlet side of the cooling tower, that is, the upper limit value T3 of the cooling water outlet temperature, the specific heat Cp of the cooling water, and the total cooling water flow rate m = 1. You. Then, when switching from the hot water supply operation to the cold water supply operation during the actual operation of the absorption chiller / heater, the opening of the three-way valve 31 on the bypass pipe 30 side is controlled to the calculated opening.
For this reason, the higher the temperature of the cooling water on the inlet side of the cooling water or the higher the temperature of the cooling water on the outlet side of the condenser, the larger the opening degree of the three-way valve 31 on the bypass pipe side by the control device 32 becomes. The opening degree of the three-way valve 31 can be controlled in accordance with the above, the cooling water outlet temperature is reliably suppressed to be lower than the upper limit T3, and the cooling tower 6 can be easily prevented from being damaged by the high-temperature cooling water, and The lower the temperature of the cooling water on the inlet side of the cooling water or the lower the temperature of the cooling water on the outlet side of the condenser, the smaller the opening degree of the three-way valve 31 on the bypass pipe side by the control device 32 becomes. The amount of cooling water flowing through the exchanger 25 and the condenser heat exchanger 26 can be increased. As a result, after switching to the cold water supply operation, the capacity of the absorber 5 and the condenser 2 can be improved in a short time according to the temperature of the cooling water, and the time required for switching to the cold water supply operation can be further reduced. be able to.

It should be noted that the present invention is not limited to the above embodiment, but can be variously implemented without departing from the gist of the present invention. For example, in each of the above embodiments, the single-effect absorption chiller / heater was described.However, even when the present invention was implemented in a double-effect absorption chiller / heater having a high-temperature regenerator and a low-temperature regenerator, The same operation and effect as the embodiment can be obtained.

As shown in FIGS. 5 and 6, two-way valves 50 and 51 are provided in the middle of the bypass pipe 30 or the cooling water pipe 24 in place of the three-way valve to switch the operation from the hot water supply operation to the cold water supply operation. At the same time, the same effect can be obtained when the opening of each valve is controlled in the same manner as the control of the opening on the bypass pipe side and the opening on the cooling water pipe side of the three-way valve in each of the above embodiments.

[0048]

According to the present invention, there is provided an absorption chiller / heater as described above. According to the first aspect of the present invention, when the operation is switched from the hot water supply operation to the chilled water supply operation, the control device detects the temperature by the temperature detector. The opening of the three-way valve is controlled based on the cooling water outlet temperature, which is the temperature of the cooling water flowing to the cooling tower, so that the high-temperature cooling water can be prevented from returning to the cooling tower as it is, and the heat exchange that forms the cooling tower It is possible to prevent members such as a vessel from being damaged, to prevent a failure of a cooling tower, a decrease in cooling capacity, and the like, and to improve safety of a cooling water circulation circuit.

The control device controls the opening of the three-way valve based on the cooling water outlet temperature detected by the temperature detector.
The opening degree control of the three-way valve by the control device changes depending on the cooling water temperature of the absorber heat exchanger and the condenser heat exchanger immediately after the operation switching, and the control from the absorber heat exchanger and the condenser heat exchanger or the cooling tower When the temperature of the cooling water is relatively low, the entire amount of the cooling water flows to the absorber heat exchanger and the condenser heat exchanger in a short time, and the switching can be shortened.

Further, it is possible to prevent the cooling water whose temperature has been lowered after the switching of the operation from suddenly flowing into the total heat exchanger heat exchanger and the condenser heat exchanger. As a result, a sudden change in the absorption capacity of the absorber and the condensation capacity of the condenser can be avoided, and hunting of the chilled water outlet temperature after operation switching can be prevented to stabilize the operation. According to the second aspect of the present invention, the degree of opening of the three-way valve on the bypass pipe side at the time of switching from the hot water supply operation to the cold water supply operation is determined in advance by the upper limit value T1 of the cooling water absorber inflow side temperature and the condensation temperature. Upper limit T2 of the outlet temperature of the vessel,
The upper limit value of the cooling water on the cooling tower inlet side, that is, the upper limit value T3 of the cooling water outlet temperature, the specific heat Cp of the cooling water, and the total cooling water flow rate m =
1, the opening of the three-way valve on the bypass pipe side is controlled to the previously calculated opening when switching from the hot water supply operation to the cold water supply operation during the actual operation of the absorption chiller / heater. As a result, when the temperature of the cooling water on the inlet side of the cooling water or the temperature of the cooling water on the outlet side of the condenser has risen to near the upper limit values T1 and T2, or the temperature of the cooling water on the inlet side of the absorber and the temperature of the condenser. Even when the temperature of the cooling water on the outflow side rises to near the upper limit values T1 and T2, the cooling water outlet temperature is reliably suppressed to be lower than the upper limit value T3, so that the cooling tower is easily damaged by the high-temperature cooling water. Can be avoided. Further, it is possible to prevent a failure of the cooling tower, a decrease in cooling capacity, and the like, and to improve the safety of the cooling water circulation circuit.

The control device operates when the cooling water outlet temperature detected by the temperature detector drops to the lower limit temperature. The opening of the three-way valve on the cooling water pipe side is set to 100%, and the opening degree on the bypass pipe side is set to 0%. %, The entire amount of the cooling water discharged from the cooling water pump flows to the absorber heat exchanger and the condenser heat exchanger, and the operation can be switched to the normal cold water supply operation in a short time. Also,
According to the third aspect of the present invention, the degree of opening of the three-way valve on the bypass pipe side at the time of switching from the hot water supply operation to the cold water supply operation is determined by the coolant inlet temperature t1 of the cooling water, the outlet temperature t2 of the condenser, The upper limit value of the cooling water on the inlet side of the cooling tower, that is, the upper limit value T3 of the cooling water outlet temperature, the specific heat Cp of the cooling water, and the total cooling water flow rate m = 1
When the operation is switched from the hot water supply operation to the cold water supply operation during the actual operation of the absorption chiller / heater, the opening of the three-way valve on the bypass pipe side is controlled to the calculated opening.
Therefore, as the temperature of the cooling water on the inlet side of the cooling water or the temperature on the outlet side of the condenser becomes higher, the opening degree of the three-way valve on the bypass pipe side by the control device becomes larger, and the three-way valve is opened in accordance with the respective temperatures. The opening degree can be controlled, the cooling water outlet temperature is reliably kept lower than the upper limit value T3, the cooling tower can be easily prevented from being damaged by the high-temperature cooling water, and the cooling water is supplied to the absorber inlet side. The lower the temperature of the cooling water or the lower the cooling water temperature on the outlet side of the condenser, the smaller the opening of the bypass pipe side of the three-way valve becomes, and accordingly the cooling water flowing to the absorber heat exchanger and the condenser heat exchanger Can be increased. As a result, after switching to the cold water supply operation, the capacity of the absorber and the condenser can be improved in a short time according to the temperature of the coolant, and the time required for switching to the cold water supply operation can be further reduced. it can.

According to the present invention, when the operation is switched from the hot water supply operation to the cold water supply operation, the control device controls the opening of the three-way valve based on the cooling water outlet temperature detected by the temperature detector. However, it is possible to prevent high-temperature cooling water from returning to the cooling tower, avoid damage to members such as a heat exchanger that constitute the cooling tower, and improve the safety of the cooling water circulation circuit. Of course, the cooling tower starts operation immediately after switching from the hot water supply operation to the cold water supply operation,
The cooling water returned to the cooling tower releases heat immediately after the switching and is cooled, flows to the absorber heat exchanger and the condenser heat exchanger, and can promote the temperature decrease of each heat exchanger.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an absorption chiller / heater showing an embodiment of claims 1 and 4 of the present invention.

FIG. 2 is a diagram illustrating a relationship between a cooling water outlet temperature, a bypass opening of a three-way valve, and a cooling water outlet opening.

FIG. 3 is a schematic configuration diagram of an absorption chiller / heater according to a second embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of an absorption chiller / heater according to a third embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of an absorption chiller / heater showing another embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of an absorption chiller / heater showing another embodiment of the present invention.

[Explanation of symbols]

 A Absorption chiller / heater 1 Regenerator 2 Condenser 4 Evaporator 5 Absorber 6 Cooling tower 22 Cooling water pipe 23 Cooling water pipe 24 Cooling water pipe 27 Cooling water pump 30 Bypass pipe 31 Three-way valve 32 Control device 33 First temperature Detector 40 Second temperature detector 41 Third temperature detector

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-313647 (JP, A) JP-A-5-248723 (JP, A) JP-A-63-61849 (JP, A) 80160 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00 306

Claims (4)

(57) [Claims] 1. A recirculator, a condenser, an evaporator, an absorber and the like are connected by piping to form a circulation path for a refrigerant and an absorbing liquid, and an absorber, a condenser, a cooling tower, and a cooling water pump are sequentially connected by piping. In the absorption chiller / heater that switches between a chilled water supply operation that supplies chilled water from the evaporator and a chilled water supply operation that sends refrigerant vapor from the regenerator to the evaporator and supplies hot water from the evaporator, forming a cooling water circulation path. A bypass pipe connected between the downstream side of the cooling water pump and the cooling water circulation path from the condenser to the cooling tower through a control valve and bypassing the absorber and the condenser, and cooling water flowing into the cooling tower. A temperature detector for detecting the temperature of the
A control device for controlling the opening of the control valve so that the flow rate of the cooling water flowing through the bypass pipe increases with an increase in the temperature detected by the temperature detector after switching from the hot water supply operation to the cold water supply operation. An absorption chiller / heater. 2. A recirculator, a condenser, an evaporator, an absorber and the like are connected by pipes to form a circulation path of a refrigerant and an absorbing liquid, and an absorber, a condenser, a cooling tower, and a cooling water pump are sequentially connected by pipes. In the absorption chiller / heater that switches between a chilled water supply operation that supplies chilled water from the evaporator and a chilled water supply operation that sends refrigerant vapor from the regenerator to the evaporator and supplies hot water from the evaporator, forming a cooling water circulation path. A bypass pipe connected between the downstream side of the cooling water pump and the cooling water circulation path from the condenser to the cooling tower through a control valve and bypassing the absorber and the condenser, and cooling water flowing into the cooling tower. A temperature detector for detecting the temperature of the
After switching from the hot water supply operation to the cold water supply operation, until the temperature detected by the temperature detector drops to the set temperature, the following expression is used. Mx Cp x T3 = m1 x Cp x T1 + (m-m1) x C
m = 1 in p × T2, T1 = upper limit value of cooling water absorber inlet side temperature,
T2 = upper limit value of the outlet temperature of the condenser, T3 = upper limit value of the cooling water inlet side temperature of the cooling water, and Cp = control the ratio of the cooling water flowing into the bypass pipe obtained by inputting the specific heat of the cooling water to m1. A control device for controlling an opening of the valve on a side of a bypass pipe. 3. A recirculator, a condenser, an evaporator, an absorber, and the like are connected by piping to form a circulation path of the refrigerant and the absorbing liquid, and an absorber, a condenser, a cooling tower, and a cooling water pump are sequentially connected by piping. In the absorption chiller / heater that switches between a chilled water supply operation that supplies chilled water from the evaporator and a chilled water supply operation that sends refrigerant vapor from the regenerator to the evaporator and supplies hot water from the evaporator, forming a cooling water circulation path. A bypass pipe connected between the downstream side of the cooling water pump and the cooling water circulation path from the condenser to the cooling tower via a control valve to bypass the absorber and the condenser, and to cool the inlet side of the absorber. A cooling water inlet temperature detector for detecting the water temperature, a cooling water outlet temperature detector for detecting the cooling water temperature at the outlet side of the condenser, and a temperature signal from the cooling water outlet temperature detector and the cooling water inlet temperature detector. Input to switch from hot water supply operation to cold water supply operation. After replacement, the following equation: m × Cp × T3 = m1 × Cp × T1 + (m−m1) × C
m = 1, T1 = detected temperature of cooling water inlet temperature detector, p × T2, T
2 = detected temperature of the cooling water outlet temperature detector, T3 = upper limit value of the temperature of the cooling water at the inlet of the cooling tower, and Cp = ratio m1 of the cooling water flowing to the bypass pipe obtained by inputting the specific heat of the cooling water. A control device for controlling an opening degree of a control valve on a bypass pipe side, wherein the absorption chiller / heater is provided. 4. A recirculator, a condenser, an evaporator, an absorber, and the like are connected by piping to form a circulation path for the refrigerant and the absorbing liquid, and an absorber, a condenser, a cooling tower, and a cooling water pump are sequentially connected by piping. In the absorption chiller / heater that switches between a chilled water supply operation that supplies chilled water from the evaporator and a chilled water supply operation that sends refrigerant vapor from the regenerator to the evaporator and supplies hot water from the evaporator, forming a cooling water circulation path. A bypass pipe connected between the downstream side of the cooling water pump and the cooling water circulation path from the condenser to the cooling tower through a control valve and bypassing the absorber and the condenser, and cooling water flowing into the cooling tower. A temperature detector for detecting the temperature of the
After switching from the hot water supply operation to the cold water supply operation, the opening of the control valve is controlled and the cooling tower is operated so that the flow rate of the cooling water flowing through the bypass pipe increases as the temperature detected by this temperature detector increases. An absorption chiller / heater comprising a control device for continuously outputting a signal.