JPH08152225A - Absorption water cooling-heating machine - Google Patents

Abstract

PURPOSE: To prevent breakdown of a member such as a heat exchanger constituting a cooling tower. CONSTITUTION: A bypass pipe 30 bypassing an absorber 5 and a condenser 2 of an absorption water cooling-heating machine is connected between the downstream side of a cooling water pump 27 and a cooling water circulation piping 24 stretching from the condenser 2 to a cooling tower 6, through the intermediary of a three-way valve 31. A temperature detector 33 detecting the temperature of cooling water flowing into the cooling tower 6 is provided and the opening of the three-way valve 31 is controlled by a control device 32 so that the flow rate of the cooling water flowing to the bypass pipe 30 be increased as the temperature detected by the temperature detector 33 becomes high, after switchover from a hot water supply operation to a cold water supply operation. Thereby it is avoided that cooling water of a high temperature flows to the cooling tower 6.

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 an absorber, a condenser and a cooling tower are connected by piping to form a cooling water circulation passage.

[0002]

2. Description of the Related Art For example, in Japanese Unexamined Patent Publication No. 5-248723, an auxiliary pipe connects a downstream side of a cooling water circulation pump and a communication pipe line from a condenser to a cooling tower, and an opening / closing control means is connected to the auxiliary pipe. The opening / closing control means is temporarily opened at the time of switching from the heating operation mode to the cooling operation mode, and the low-temperature cooling water from the cooling tower is caused to flow to the connecting pipeline via the auxiliary pipe, and the high-temperature cooling from the condenser is performed. Mix with water to reduce temperature. Then, after a certain period of time, after the high temperature state of the cooling water is eliminated, the absorption type cold / hot water unit is disclosed in which the opening / closing control means is closed to shift to normal cooling operation. Therefore, when the heating operation mode is switched 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]

SUMMARY OF THE INVENTION In the above conventional technique,
Regardless of the temperature of the cooling water flowing out of the condenser when switching from the heating operation mode to the cooling operation mode, the opening / closing 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. Therefore, for example, even when the heating operation mode time is short and the cooling water temperature of the absorber and the condenser is not high, the amount of cooling water flowing to the absorber and the condenser decreases for a certain period of time, The refrigerant absorption capacity of the condenser and the condensation capacity of the refrigerant vapor of the condenser do not increase, and as a result,
There is a problem that the switching to the cooling operation mode is delayed.

Further, when the opening / closing control means is closed after the lapse of the above-mentioned certain 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 refrigerating capacity also increases rapidly. For this reason, the temperature of the cold water flowing out from the evaporator also sharply decreases, and the cold water outlet temperature falls below a set temperature, and problems such as hunting occurring at the cold water outlet temperature occur.

An object of the present invention is to smoothly switch the heating operation mode (hot water supply operation) to the cooling operation mode (cool water supply operation) while avoiding damage to the cooling tower.

[0006]

In order to solve the above-mentioned problems, the present invention according to claim 1 circulates a refrigerant and an absorbing liquid by connecting a regenerator, a condenser, an evaporator, an absorber and the like by piping. A cooling water supply operation that supplies cold water from the evaporator and a refrigerant vapor from the regenerator to the evaporator by forming a channel, connecting the absorber, condenser, cooling tower and cooling water pump in sequence to form a cooling water circulation channel. In an absorption chiller-hot water machine that switches between hot water supply operation to supply hot water from the evaporator and a hot water supply operation, it is connected via a control valve between the cooling water pump downstream side and the cooling water circulation path from the condenser to the cooling tower. The bypass pipe that bypasses the absorber and condenser, the temperature detector that detects the temperature of the cooling water flowing into the cooling tower, and the temperature detected by this temperature detector after switching from the hot water supply operation to the cold water supply operation Flows into the bypass pipe as the 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.

Further, in the invention of claim 2, 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 are provided. Switching between a cold water supply operation that supplies cold water from the evaporator and a hot water supply operation that supplies refrigerant vapor from the regenerator to the evaporator to supply hot water from the evaporator by forming a cooling water circulation path by sequentially connecting water pumps In the absorption chiller-heater to be performed by, a bypass pipe 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, and bypassing the absorber and the condenser. After the temperature detector that detects the temperature of the cooling water that flows into the cooling tower and after switching from the hot water supply operation to the cold water supply operation, the following formula m × Cp × T3 = m1 x Cp x T1 + (m-m1) x C
m = 1 in p × T2, T1 = upper limit value of the cooling water absorber inflow side temperature,
T2 = the upper limit value of the outlet side temperature of the condenser, T3 = the upper limit value of the cooling tower inlet side temperature of the cooling water, and Cp = the cooling water flow rate to the bypass pipe obtained by inputting the specific heat of the cooling water. The present invention provides an absorption chiller-heater equipped with a control device that controls the opening of the valve on the bypass pipe side.

Further, in the invention of claim 3, 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 are provided. Switching between a cold water supply operation that supplies cold water from the evaporator and a hot water supply operation that supplies refrigerant vapor from the regenerator to the evaporator to supply hot water from the evaporator by forming a cooling water circulation path by sequentially connecting water pumps In the absorption chiller-heater to be performed by, a bypass pipe 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, and bypassing the absorber and the condenser. Cooling water inlet temperature detector that detects the cooling water temperature on the inlet side of the absorber, cooling water outlet temperature detector that detects the cooling water temperature on the outlet side of the condenser, cooling water outlet temperature detector and cooling water inlet Supply hot water by inputting temperature signal from temperature detector After switching to the cold water supply operation from a converter,
The following formula m × Cp × T3 = m1 × Cp × T1 + (m−m1) × C
In p × T2, m = 1, T1 = cooling water inlet temperature detector detection temperature, T
2 = the temperature detected by the cooling water outlet temperature detector, T3 = the upper limit of the temperature of the cooling water at the inlet side of the cooling tower, and Cp = the ratio m1 of the cooling water flowing to the bypass pipe obtained by inputting the specific heat of the cooling water. The present invention provides an absorption chiller-heater equipped with a control device that controls the opening of the control valve on the bypass pipe side.

Further, according to the invention of claim 4, 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 are provided. Switching between a cold water supply operation that supplies cold water from the evaporator and a hot water supply operation that supplies refrigerant vapor from the regenerator to the evaporator to supply hot water from the evaporator by forming a cooling water circulation path by sequentially connecting water pumps In the absorption chiller-heater to be performed by, a bypass pipe 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, and bypassing the absorber and the condenser. The temperature detector that detects the temperature of the cooling water flowing into the cooling tower, and the flow rate of the cooling water flowing through the bypass pipe as the temperature detected by this 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 invention of claim 1, when the hot water supply operation is switched 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,
To the cooling tower, the high-temperature cooling water from the absorption chiller-heater and the cooling-temperature cooling water from the bypass pipe are mixed appropriately and the temperature is lowered and returned, and the members such as the heat exchanger that compose the cooling tower are damaged. This makes it possible to prevent the failure of the cooling tower, the deterioration of the cooling capacity, etc., and improve the safety of the cooling water circulation circuit.

Further, 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 preset to the upper limit value T of the cooling water absorber inflow side temperature.
1. Based on the upper limit value T2 of the outlet side temperature of the condenser, the upper limit value of the cooling water 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 actual absorption chiller-heater is operated, when the hot water supply operation is switched to the cold water supply operation, the opening of the valve on the bypass pipe side is controlled to the previously calculated opening. When the temperature on the inlet side of the absorber of the cooling water has risen to near the upper limit value T1, the temperature of the cooling water on the outlet side of the condenser rises to near the upper limit value T2, or the temperature of the cooling water on the inlet side of the absorber And the cooling water temperature on the outflow side of the condenser is the upper limit value T1,
Even when the temperature rises to near T2, the cooling water outlet temperature can be reliably suppressed to be lower than the upper limit value T3, and it becomes possible to easily prevent the cooling tower from being damaged by the high temperature cooling water.

Further, according to the third aspect of the 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 such that the cooling water absorber inlet temperature t1 and the condenser outflow. 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 the hot water supply operation is switched to the cold water supply operation during the actual operation of the absorption chiller-heater, the opening degree of the valve on the bypass pipe side is controlled to the calculated opening degree. Therefore, the higher the temperature of the cooling water on the inlet side of the absorber or the higher the temperature of the cooling water on the outlet side of the condenser, the greater the degree of opening of the valve on the bypass pipe side by the control device. The opening degree of the valve can be controlled, the cooling water outlet temperature can be reliably suppressed to be lower than the upper limit value T3, and the cooling tower can be easily prevented from being damaged by the high temperature cooling water.

Further, according to the invention of claim 4, when the hot water supply operation is switched 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. Therefore, it is possible to prevent the high-temperature cooling water from returning to the cooling tower, and it is possible to prevent the members such as the heat exchanger that constitute the cooling tower from being damaged. Further, 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 radiates heat immediately after switching and is cooled and flows to the absorber and the condenser, respectively. It is possible to accelerate the temperature decrease of

[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 the refrigerant, and lithium bromide (LiBr) solution is used as the absorbing liquid (solution). In the figure, 1 is a regenerator equipped with a gas burner 1B, 2 is a condenser,
Reference numeral 3 is a lower body accommodating the evaporator 4 and absorber 5, 6 is a cooling tower, 7 is a heat exchanger, 8 to 11 are absorption liquid pipes, 12 is an absorption liquid pump, 13 is a regenerator 1 and a heat exchanger 7. Between the absorption liquid pipe 10 and the absorbent liquid pipe branching to the absorber 5 of the lower body 3, 14 is a first on-off valve provided in the absorption liquid pipe 13, and 15 and 16 are refrigerants. Piping, 17 is a refrigerant circulation pipe, 18 is a refrigerant pump, 20 is a refrigerant vapor pipe branching from the middle of the refrigerant pipe 15 to the gas phase portion of the absorber 5 of the lower body 3, 21 is an intermediate part of the refrigerant vapor pipe 20. It is a second on-off valve provided.

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

Reference numeral 32 is an absorption chiller-heater controller, and 33 is 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 composed of, for example, a microcomputer, and the storage device 34 stores in the cooling water the inflow temperature of the cooling tower 6, that is, the detection temperature of the first temperature detector 33, the bypass pipe side opening degree of the three-way valve 31, and the cooling water outlet. The relationship with the side opening (opening on the cooling water pipe side) as shown in FIG. 2 is stored in advance. Then, the control device 32 outputs an opening signal to the three-way valve 31 based on the relationship of FIG. 2 when switching from the hot water supply operation to the cold water supply operation. In addition, 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, 29.
Outputs an open signal during cold water supply operation and outputs a closed signal during hot water supply operation. Further, the control device 32 is the cooling water pump 2
During the operation of 7, the operation signal is output to the fan motor 6M that drives the blower fan 6F of the cooling tower 6.

Reference numeral 35 is a cold / hot water pipe connected to the evaporator 3, 36 is an evaporator heat exchanger, and 37 is a cold / hot water pump. A cold / hot water temperature detector 38 is provided on the evaporator 3 outflow side of the cold / hot water pipe 35 to detect the outlet temperature of the cold / hot water. 1st, 2nd, 3rd, 4th based on driving
A program for controlling the opening / closing of the on-off valve, a program for controlling the heating amount of the burner 1B based on the hot / cold water outlet temperature, and the like are stored in advance.

The operation of the absorption chiller-heater constructed as above will be described below. During cold water supply operation,
The controller 32 outputs a closing signal to the first and second opening / closing valves 14 and 21, and outputs a closing signal to the third and fourth opening / closing valves 28 and 29. Further, the control device 32 outputs a combustion signal to the burner 1B, and the burner 1B burns. Then, in the regenerator 1, the absorbent having a low concentration (hereinafter referred to as the rare absorbent) is heated, and the refrigerant is separated from the rare absorbent and evaporated. 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 then flows to the evaporator 3 via the refrigerant pipe 16. Then, the refrigerant liquid exchanges heat with the cold water in the evaporator heat exchanger 35 to evaporate, and the cold water is cooled by the heat of vaporization and supplied to the load. In addition, the refrigerant evaporated in the evaporator 3 flows to the absorber 5 and is dispersed as a thick absorption liquid (hereinafter referred to as a concentrated liquid).
Is absorbed by

The rare absorbent which has become thin in concentration by absorbing the refrigerant in the absorber 5 is sent to the regenerator 1 through the heat exchanger 7 as the temperature thereof rises by the operation of the absorber pump 12. The rare absorbent flowing into the regenerator 1 is heated by the burner 1B,
The concentrated liquid, which has a high concentration, is separated from the refrigerant and evaporated, and the concentrated liquid is lowered in temperature through the heat exchanger 7 and is cooled to flow into the absorber 5,
It is scattered.

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

When the cold water supply operation is performed as described above and the season is changed from the summer when the cooling operation is performed, for example, when it becomes autumn or winter and the heating operation by the hot water supply operation is required, the administrator controls the controller 32. Changeover switch 32
Operate S. The control device 32 operates by operating the changeover switch 32S, outputs an open 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, and the cooling tower 6 The operation stop signal is output to.

By the output of the above 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 the refrigerant separated in the regenerator 1 flows to the evaporator 4 and flows from the regenerator 1 to the absorber 5 via the absorption liquid pipes 10 and 13. In addition, 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 and the temperature rises to become hot water which is supplied to the load and switched 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, the fuel supply amount to the burner 1B is adjusted based on this signal, and the heating amount of the burner 1B is controlled.

When the hot water supply operation is performed as described above and, for example, hot water is supplied to perform the heating operation of the office or the store, the room temperature of the office or the room temperature of the store rises and the heating operation is performed. When switching from the heating operation to the cooling operation, that is, when switching from the heating operation to the cooling operation, that is, when switching from the heating operation to the cooling water supply operation, the control device 32 operates, and
A closing signal is output to the second opening / closing valves 14 and 21, an opening signal is output to the third and fourth opening / closing valves 28 and 29, and an operation signal is output to the fan motor 6M of the cooling tower 6 and the cooling water pump 27.

The first and second on-off valves 1 are operated by the closing signal.
4, 21 are closed, the third and fourth on-off valves 28, 29 are opened,
In addition, the cooling tower 6 and the cooling water pump 27 start operation,
The cold water supply operation as described above starts. In addition, 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 the hot water supply operation is switched 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, the temperature of which has risen and increased during the hot water supply operation, is pushed out by the cooling water discharged from the cooling water pump 27. Be done. Further, a part of the low temperature cooling water accumulated 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 main body of the absorption chiller-heater and the low temperature cooling water flowing through the bypass pipe 30 are combined by the three-way valve 31 and mixed and flow into the cooling tower 6. In the cooling tower 6, the inflowing cooling water is cooled, its temperature is lowered, and it flows out, and 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 controller 32 controls the opening degree of the three-way valve 31 based on the detected temperature as described above. After the switching from the hot water supply operation to the cold water supply operation, when the temperature of the cooling water flowing from the main body of the absorption chiller / hot water machine is high and the temperature of the cooling water flowing to the cooling tower 6 is high, based on the relationship of FIG. The control device 32 is the bypass pipe 3 of the three-way valve 31.
The opening degree on the 0 side is controlled to be large and the opening degree on the cooling water pipe 24 side is controlled to be 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 the cooling water outlet temperature) is 50 ° C. or higher, the control device 32 bypasses the three-way valve 31. The opening degree on the pipe 30 side is controlled to 100%, and the opening degree on the cooling water pipe 24 side is controlled to 0%. Therefore, all 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 higher, for example, the opening of the three-way valve 31 on the bypass pipe 30 side is controlled to 95% and the opening of the cooling water pipe 24 side is controlled to 55% to gradually cool the cooling water. Absorber heat exchanger 2
5 and the condenser heat exchanger 26 side, the cooling water outlet temperature is gradually decreased, abrupt change of the cooling water outlet temperature can be prevented, and the opening degree of each side of the three-way valve 31 is rapidly changed. Fluctuations can be avoided.

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

According to the first embodiment of the present invention described above, when the hot water supply operation is switched to the cold water supply operation, the control device 32 is based on the cooling water outlet temperature detected by the first temperature detector 33. By controlling the opening degree of the three-way valve 31, it is possible to prevent high-temperature cooling water from returning to the cooling tower 6, and it is possible to avoid damaging members such as the heat exchanger that compose the cooling tower 6. It is possible to prevent the failure, the deterioration of the cooling capacity, etc., and improve the safety of the cooling water circulation circuit.

Further, the control device 32 uses the first temperature detector 3
Since the opening degree of the three-way valve 31 is controlled based on the cooling water outlet temperature detected by No. 3, the control device 32 is 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 opening control of the three-way valve 31 due to changes in the temperature of the cooling water from the absorber heat exchanger 25 and the condenser heat exchanger 26 or the cooling tower 6, the total amount of cooling water is absorbed in a short time. The heat flows into the heat exchanger 25 and the heat exchanger 26 of the condenser, and it is possible to switch 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 the switching from the hot water supply operation to the cold water supply operation, the cooling water returning to the cooling tower 6 is radiated and cooled immediately after the switching, and the absorber heat exchanger 25 and It can flow to the condenser heat exchanger 26 to promote the temperature reduction of each heat exchanger.

Immediately after switching from the hot water supply operation to the cold water supply operation, the control device 32 causes the first temperature detector 3 to operate.
Since the opening degree of the three-way valve 31 is controlled based on the cooling water outlet temperature detected by No. 3, all the cooling water whose temperature has dropped after the switching of the operation is absorbed in the absorber heat exchanger 25 and the condenser heat exchanger 26.
It is possible to prevent sudden flow. As a result, the absorber 5
It is possible to avoid a sudden change in the absorption capacity of the condenser and the condensation capacity of the condenser 2 and prevent hunting of the cold water outlet temperature after the operation switching to stabilize the operation.

Further, even when the hot water supply operation is switched to the cold water supply operation and the cooling water outlet temperature is high, the entire quantity of the cooling water discharged from the cooling water pump 27 is not passed through the bypass pipe 30, but the cooling water is supplied. Hunting of opening and closing of the three-way valve 33 that occurs when the entire amount of cooling water is caused to flow to the bypass pipe 30 when the cooling water outlet temperature is high when flowing little by little to the absorber heat exchanger 25 and the condenser heat exchanger 26. That is, when the opening degree of the three-way valve 31 on the bypass pipe 30 side is set to 100% and the cooling water pipe 24 side is set to 0% to flow the entire amount of cooling water to the bypass pipe 30, and on the bypass pipe 30 side of the three-way valve 31. The opening degree can be made smaller than 100%, and it is possible to avoid repetition in a short time when the cooling water pipe 24 side is opened by that amount and a part of the cooling water is allowed to flow to the main body of the absorption chiller-heater, and as a result, the three-way valve 31 Prevents breakdown Te, it is possible to simplify the maintenance work.

The second embodiment of the present invention will be described below with reference to FIG. 3 that are the same as those in FIG. 1 are the same as those in FIG. 1, and a detailed description thereof will be omitted. Instead of the relationship between the cooling water outlet temperature of FIG. 2 and the opening degree of the bypass pipe side and the opening degree of the cooling water pipe side of the three-way valve 31 in FIG. Valve 31
Of the bypass pipe 30 side is controlled to a ratio m1 of the cooling water flow rate on the bypass pipe 30 side calculated based on the following equation 1 to the total cooling water flow rate, and the cooling water pipe 24 of the three-way valve 31 is controlled.
A program for controlling the opening on the side to be the opening obtained by subtracting the opening on the side of the bypass pipe 30 from 1 is stored.

M × Cp × T3 = m1 × Cp × T1 + (m−m1) × Cp × T2 Equation 1 In the above Equation 1, m = total cooling water flow rate = 1, T1 =
Upper limit of cooling water absorber inflow side temperature, T2 = upper limit value of condenser outflow side temperature, T3 = upper limit value of cooling water on the cooling tower inlet side, that is, upper limit value of cooling water outlet temperature, Cp = cooling water It has a specific heat. Here, the upper limit value T1 of the cooling water absorber inflow side temperature
Varies according to the climate of the area where the absorption chiller-heater is installed in advance, and is set to, for example, 32 ° C., and the upper limit value T2 of the condenser outlet temperature is the operating state of the absorption chiller-heater during hot water supply operation. Is set in advance to, for example, 80 ° C., and the upper limit value T3 of the cooling water outlet temperature is set in advance to, for example, 45 ° C., which is equal to or lower than the temperature at which damage to the cooling tower 6 can be prevented. And
By substituting the upper limit values T1, T2, and T3 into Expression 1, the opening degree m1 of the three-way valve 31 on the side of the bypass pipe 30 = 0.
73 is calculated.

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

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

At the time of switching to the cold water operation, the controller 32 operates to output a signal to the three-way valve 31, the opening degree on the bypass pipe 30 side is 73%, and the opening degree on the cooling water pipe side is 27%. Controlled. Therefore, during the cold water supply operation, that is, during the heating operation, the temperature of the absorber heat exchanger 25 and the condenser heat exchanger 2 are increased.
The hot water of No. 6 is mixed with the cold water from the bypass pipe 30 by the three-way valve 31, the temperature of the hot water is lowered, and the hot water of the No. 6 returns to the cooling tower 6. Further, part of the cold water discharged from the cooling water pump 27 is absorbed by the absorber heat exchanger 25.
And to the condenser heat exchanger 26, the temperature of the warm water that has accumulated is gradually lowered. The cooling tower 6 starts operation immediately after switching.

When the cooling water outlet temperature gradually decreases with the lapse of time and the temperature detected by the first temperature detector 33 decreases to the lower limit temperature, the controller 32 operates and outputs a signal to the three-way valve 31. To do. Therefore, the opening degree of the three-way valve 31 on the cooling water pipe 4 side becomes 100%, and the opening degree of the bypass pipe 30 side becomes 0%, and the total 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 cold water is supplied from the absorption chiller-heater as in the normal cold water supply operation.

Similarly, when the hot water supply operation is switched to the cold water supply operation, the opening degree of the three-way valve 33 is controlled in the same manner as described above. According to the second embodiment described above, the opening degree of the three-way valve 31 on the side of the bypass pipe 30 at the time of switching from the hot water supply operation to the cold water supply operation is set in advance by the above equation 1 to the absorber inflow side temperature of the cooling water. The upper limit value T1, the upper limit value T2 of the outflow side temperature of the condenser, the upper limit value of the cooling water 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 Calculated by substituting. Then, during the 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 degree of the three-way valve 31 on the bypass pipe 30 side is controlled to the previously calculated opening degree. As a result, when the temperature of the cooling water on the inflow side of the absorber rises near the upper limit value T1, when the temperature of the cooling water on the outflow side of the condenser rises near the upper limit value T2, or when the cooling water absorbs The temperature on the inlet side of the reactor and the temperature of the cooling water on the outlet side of the condenser are the upper limit values T1 and T2.
Even when the temperature rises to the vicinity, the cooling water outlet temperature can be reliably suppressed to be lower than the upper limit value T3, and the cooling tower 6 can be easily avoided from being damaged by the high temperature cooling water. Further, it is possible to prevent a failure of the cooling tower 6, a decrease in cooling capacity, etc., and improve the safety of the cooling water circulation circuit.

Further, the control device 32 uses the first temperature detector 3
When the cooling water outlet temperature detected by 3 falls to the lower limit temperature, it operates and outputs a signal to the three-way valve 31, the opening degree of the cooling water pipe 4 side of the three-way valve 31 is 100%, and the opening degree of the bypass pipe 30 side is 100%. 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, and the normal cooling water supply operation can be switched in a short time.

The third embodiment of the present invention will be described below with reference to FIG. In FIG. 4, the same symbols 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 of FIG. 2 and the opening degree of the bypass pipe side and the opening degree of the cooling water pipe side of the three-way valve 31 in FIG. The opening degree of the valve 31 on the bypass pipe 30 side is controlled to a ratio m1 of the cooling water flow rate on the bypass pipe 30 side calculated based on the following formula to the total cooling water flow rate, and on the cooling water pipe 24 side of the three-way valve 31. A program for controlling the opening to 1 by subtracting the opening on the bypass pipe 30 side is stored.

M × Cp × T3 = m1 × Cp × t1 + (m−m1) × Cp × t2 ... Equation 2 In the above Equation 2, m is the entire cooling water flow rate = 1,
t1 = cooling water absorber inlet side temperature, t2 = condenser outlet side temperature, T3 = cooling tower inlet side temperature upper limit value, that is, cooling water outlet temperature upper limit value, Cp = specific heat of 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 a temperature at which damage to the cooling tower 6 can be prevented, and is stored in the storage device 34.

A second temperature detector 40 for detecting the temperature on the inflow side of the cooling water absorber 5 is provided in the cooling water pipe 22 in the absorption chiller-heater according to the third embodiment to condense the cooling water. Third temperature detector 41 for detecting the temperature on the outflow side of the container 2
Is provided on the condenser side of the three-way valve 31 of the cooling water pipe 24. During the operation of the absorption chiller-heater configured as described above, 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 degree 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 switching, the second temperature detector 40
When the temperature of the inlet side of the cooling water detected by the detector is 30 ° C. and the temperature of the outlet side of the cooling water detected by the third temperature detector 41 is 75 ° C., the controller 32 sets m =
1, Cp = 1, T3 = 45, t1 = 30 and t2 = 70
To calculate m1 = 0.625 (62.5%). And. The control device 32 sets the opening of the three-way valve 33 on the bypass pipe side 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% control.

After that, the temperature at the outlet side 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 of the cooling water pipe side gradually increases. For example, the temperature of the cooling water absorber inflow side detected by the second temperature detector 40 is 30 ° C., and the temperature of the cooling water condenser outflow side detected by the third temperature detector 41 is 5 ° C.
When the temperature is 0 ° C., the controller 32 uses m = 1 in Equation 2 above,
Cp = 1, T3 = 45, t1 = 30 and t2 = 50 are substituted to calculate m1 = 0.250 (25.0%). And. The control device 32 sets the opening of the three-way valve 33 on the bypass pipe side to slightly larger than the calculated opening, for example, 26%, 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. It is controlled to -26 = 74%.

Further, after a lapse of time, the temperature of the cooling water on the outlet side of the condenser is equal to the upper limit temperature of the cooling water outlet temperature of 45 ° C.
Then, the controller 32 calculates m1 = 0,
The degree of opening of the bypass pipe side of the three-way valve 33 is controlled to 0%, and the degree of opening of the cooling water pipe side is controlled to 100% so that the total amount of the cooling water discharged from the cooling water pump 27 is absorbed by the absorber heat exchanger 25 and the condenser. It flows to the heat exchanger 26. As a result, cold water is supplied from the absorption chiller-heater as in the normal cold water supply operation.

According to the third embodiment described above, the opening degree 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 expressed by the above equation 2 as the cooling water absorber inlet side temperature. t1, the outflow side 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 are calculated. It When the hot water supply operation is switched to the cold water supply operation during the actual operation of the absorption chiller-heater, the opening degree of the three-way valve 31 on the bypass pipe 30 side is controlled to the calculated opening degree.
Therefore, the higher the temperature of the cooling water on the inflow side of the absorber or the higher the temperature of the cooling water on the outflow side of the condenser, the larger the opening of the control device 32 on the side of the bypass pipe of the three-way valve 31 becomes. The opening degree of the three-way valve 31 can be controlled according to the above, the cooling water outlet temperature can be reliably suppressed to be lower than the upper limit value 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 absorber, or the lower the temperature of the cooling water on the outlet side of the condenser, the smaller the opening of the control device 32 on the side of the three-way valve 31 bypass pipe. 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 capacities 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 is further shortened. be able to.

The invention of the present application is not limited to the above-described embodiments, but can be variously implemented without departing from the gist of the invention of the present application. For example, in each of the above embodiments, the single-effect absorption chiller-heater was described, but even when the present invention is carried out in a double-effect absorption chiller-heater equipped with a high temperature regenerator and a low temperature regenerator, each of the above It is possible to obtain the same effect as that of the embodiment.

Further, 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 instead of the three-way valve to switch from the hot water supply operation to the cold water supply operation. Alternatively, 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 of the three-way valve in each of the above embodiments.

[0048]

The present invention is the absorption chiller-heater as described above, and according to the invention of claim 1, when the hot water supply operation is switched to the chilled water supply operation, the controller detects 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 that flows to the cooling tower, and it is possible to avoid the high temperature cooling water from returning to the cooling tower as it is, and the heat exchange that constitutes the cooling tower. It is possible to avoid damage to members such as the vessel, prevent failure of the cooling tower, decrease in cooling capacity, etc., and improve the safety of the cooling water circulation circuit.

Further, since the control device controls the opening degree of the three-way valve based on the cooling water outlet temperature detected by the temperature detector,
The opening control of the three-way valve by the controller changes depending on the cooling water temperature of the absorber heat exchanger and the condenser heat exchanger immediately after the operation switching, and the absorber heat exchanger and 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 switching can be shortened.

Further, it is possible to prevent the cooling water whose temperature has dropped after the operation is switched from suddenly flowing to the absorber heat exchanger and the condenser heat exchanger. As a result, it is possible to avoid a sudden change in the absorption capacity of the absorber and the condensation capacity of the condenser, prevent hunting of the cold water outlet temperature after the operation switching, and stabilize the operation. According to the invention of claim 2, the opening degree 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 such that the upper limit value T1 of the cooling water absorber inflow side temperature is set in advance. Upper limit value T2 of the outflow side temperature of the vessel,
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, 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 absorber inflow side or the temperature of the cooling water on the outflow side of the condenser rises to near the upper limit values T1 and T2, or the temperature of the cooling water on the absorber inflow side and the condenser Even when the temperature of the cooling water on the outflow side has risen to near the upper limit values T1 and T2, the cooling water outlet temperature can be reliably kept lower than the upper limit value T3, and the cooling tower can be easily damaged by the high temperature cooling water. Can be avoided. Further, it is possible to prevent the failure of the cooling tower, the deterioration of the cooling capacity, etc., and improve the safety of the cooling water circulation circuit.

Further, the control device operates when the cooling water outlet temperature detected by the temperature detector falls to the lower limit temperature, the opening of the three-way valve on the cooling water pipe side is 100%, and the opening on the bypass pipe side is 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 normal cooling water supply operation can be switched in a short time. Also,
According to the invention of claim 3, the opening degree of the bypass pipe side of the three-way valve at the time of switching from the hot water supply operation to the cold water supply operation is the absorber inlet side temperature t1 of the cooling water, the outlet side 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.
The opening degree of the three-way valve on the bypass pipe side is controlled to the calculated opening degree when switching from the hot water supply operation to the cold water supply operation during the actual operation of the absorption chiller-heater.
For this reason, the higher the temperature of the cooling water on the inlet side of the absorber or the higher the temperature on the outlet side of the condenser, the greater the degree of opening of the bypass pipe side of the three-way valve by the control device. The opening degree can be controlled, the cooling water outlet temperature can be surely kept lower than the upper limit value T3, and the cooling tower can be easily prevented from being damaged by the high temperature cooling water, and the cooling water absorber inflow side The lower the temperature of, or the lower the temperature of the cooling water on the outflow side of the condenser, the smaller the opening of the three-way valve on the bypass pipe side, and the cooling water flowing to the absorber heat exchanger and the condenser heat exchanger correspondingly. The amount of can be increased. As a result, after switching to the cold water supply operation, the capacities of the absorber and the condenser 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 shortened. it can.

Further, according to the invention of claim 4, when the hot water supply operation is switched to the cold water supply operation, the control device controls the opening degree of the three-way valve based on the cooling water outlet temperature detected by the temperature detector. However, it is possible to avoid returning high-temperature cooling water to the cooling tower, avoid damage to members such as the heat exchanger that configure the cooling tower, and improve the safety of the cooling water circulation circuit. Of course, 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 radiates heat immediately after 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 drawings]

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

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

FIG. 3 is a schematic configuration diagram of an absorption chiller-heater showing an embodiment of claim 2 of the present invention.

FIG. 4 is a schematic configuration diagram of an absorption chiller-heater showing an embodiment of claim 3 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 according to 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

Claims (4)

[Claims] 1. A regenerator, a condenser, an evaporator, an absorber, etc. are connected by piping to form a circulation path for a refrigerant and an absorption liquid, and an absorber, a condenser, a cooling tower, and a cooling water pump are connected in order by piping. In the absorption chiller-heater, which forms a cooling water circulation path by switching between cold water supply operation in which cold water is supplied from the evaporator and hot water supply operation in which refrigerant vapor is sent from the regenerator to the evaporator and hot water is supplied from the evaporator , A bypass pipe connected by way of 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, bypassing the absorber and the condenser, and the cooling water flowing into the cooling tower. Temperature detector to detect the temperature of
After switching from the hot water supply operation to the cold water supply operation, the control device controls the opening degree of the control valve so that the flow rate of the cooling water flowing through the bypass pipe increases as the temperature detected by the temperature detector increases. Absorption chiller / heater characterized by 2. A regenerator, a condenser, an evaporator, an absorber and the like are connected by piping to form a circulation path for a refrigerant and an absorption liquid, and an absorber, a condenser, a cooling tower and a cooling water pump are connected in order by piping. In the absorption chiller-heater, which forms a cooling water circulation path by switching between cold water supply operation in which cold water is supplied from the evaporator and hot water supply operation in which refrigerant vapor is sent from the regenerator to the evaporator and hot water is supplied from the evaporator , A bypass pipe connected by way of 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, bypassing the absorber and the condenser, and the cooling water flowing into the cooling tower. Temperature detector to detect the temperature of
After switching from the hot water supply operation to the cold water supply operation, the following formula is applied until the temperature detected by the temperature detector falls to the set temperature: m × Cp × T3 = m1 × Cp × T1 + (m-m1) × C
m = 1 in p × T2, T1 = upper limit value of the cooling water absorber inflow side temperature,
T2 = the upper limit value of the outlet side temperature of the condenser, T3 = the upper limit value of the cooling tower inlet side temperature of the cooling water, and Cp = the cooling water flow rate to the bypass pipe obtained by inputting the specific heat of the cooling water. An absorption chiller-heater, comprising: a control device that controls the opening of the valve on the bypass pipe side. 3. A regenerator, a condenser, an evaporator, an absorber and the like are connected by piping to form a circulation path for a refrigerant and an absorption liquid, and an absorber, a condenser, a cooling tower and a cooling water pump are connected in order by piping. In the absorption chiller-heater, which forms a cooling water circulation path by switching between cold water supply operation in which cold water is supplied from the evaporator and hot water supply operation in which refrigerant vapor is sent from the regenerator to the evaporator and hot water is supplied from the evaporator , A bypass pipe connected by 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, bypassing the absorber and the condenser, and cooling the inflow side of the absorber. Temperature signals from the cooling water inlet temperature detector that detects the water temperature, the cooling water outlet temperature detector that detects the cooling water temperature on the outlet side of the condenser, 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 formula m × Cp × T3 = m1 × Cp × T1 + (m−m1) × C
In p × T2, m = 1, T1 = cooling water inlet temperature detector detection temperature, T
2 = the temperature detected by the cooling water outlet temperature detector, T3 = the upper limit of the temperature of the cooling water at the inlet side of the cooling tower, and Cp = the ratio m1 of the cooling water flowing to the bypass pipe obtained by inputting the specific heat of the cooling water. An absorption chiller-heater comprising: a control device that controls an opening of a control valve on a bypass pipe side. 4. A regenerator, a condenser, an evaporator, an absorber and the like are connected by piping to form a circulation path for a refrigerant and an absorption liquid, and an absorber, a condenser, a cooling tower and a cooling water pump are connected in sequence by piping. In the absorption chiller-heater, which forms a cooling water circulation path by switching between cold water supply operation in which cold water is supplied from the evaporator and hot water supply operation in which refrigerant vapor is sent from the regenerator to the evaporator and hot water is supplied from the evaporator , A bypass pipe connected by way of 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, bypassing the absorber and the condenser, and the cooling water flowing into the cooling tower. Temperature detector to detect the temperature of
After switching from the hot water supply operation to the cold water supply operation, the opening of the control valve is controlled so that the flow rate of the cooling water flowing through the bypass pipe increases as the temperature detected by this temperature detector rises, and the operation goes to the cooling tower. An absorption chiller-heater, comprising: a controller that continuously outputs a signal.