JP2706870B2 - Cooling control device for 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 a method and apparatus for controlling the cooling of an absorption chiller / heater, and more particularly to the cooling control of an absorption chiller / heater capable of avoiding an inoperable state due to a decrease in refrigerant temperature of an evaporator at the start of cooling operation. Method and apparatus.

[0002]

2. Description of the Related Art This type of absorption chiller / heater is provided as an apparatus for performing a refrigerating operation or the like by directly consuming high-temperature heat energy.

FIG. 6 is a system diagram showing such a conventional absorption chiller / heater.

In FIG. 6, the dilute solution of the absorber 111 is:
Pressurized by the solution pump 113, the low-temperature heat exchanger 11
5. High-temperature regenerator 1 after heat exchange in high-temperature heat exchanger 117
19 is supplied. The solution heated by the burner (not shown) in the high-temperature regenerator 119 enters the separator 121 and is separated into the refrigerant vapor and the primary concentrated solution in the separator 121. The primary concentrated solution separated by the separator 121 exchanges heat with the dilute solution in the high-temperature heat exchanger 117, and is further heated in the low-temperature regenerator 123 to become a concentrated solution.
The liquid is supplied to the concentrated liquid distributor 124 installed at the upper part inside the absorber 111 via the line 15. This concentrated liquid distributor 124
Is supplied to the cooling pipe 1 by the concentrated liquid distributor 124.
It is distributed and dropped to 27. The concentrated liquid absorbs the refrigerant vapor while flowing down the surface of the cooling pipe 127. The absorption heat generated at this time is removed by the cooling water flowing through the absorption cooling pipe 127.

[0005] The refrigerant vapor generated in the separator 121 is guided to a low-temperature regenerator 123, where the primary concentrated solution is heated again to exchange heat and then to a condenser 125. The vapor generated from the primary concentrated solution in the low-temperature regenerator 123
It is led to 5. A condenser cooling pipe 129 is provided inside the condenser 125. The condenser 125 exchanges heat with cooling water flowing through the condenser cooling pipe 129 to dissipate heat of condensation, thereby cooling the refrigerant vapor to condense and liquefy. . The condenser 125
The refrigerant liquid liquefied in is guided to the refrigerant distributor 134 of the evaporator 133. The refrigerant liquid in the refrigerant distributor 134 is scattered by the refrigerant distributor 134 to the evaporator heat transfer tubes 135 to evaporate, and removes latent heat of evaporation from water flowing through the evaporator heat transfer tubes 135. Thereby, cold water 137 can be obtained from the evaporator heat transfer tube 135, and cooling or the like can be performed with the cold water 137.

Incidentally, in the case of the above absorption chiller / heater,
In the operation in a state where the temperature of the cooling water flowing through the absorption cooling pipe 127 becomes low and has an absorbing power, problems such as freezing of the refrigerant and crystallization of the solution may occur, and the operation may be disabled. For this reason, in order to avoid the freezing of the refrigerant and the crystallization of the solution, control is performed by the evaporator refrigerant temperature.

In FIG. 6, a control system for controlling the evaporator refrigerant temperature in order to avoid the above-described freezing of the refrigerant and crystallization of the solution is configured as follows. That is,
The bypass pipe 141 communicates between the concentrated solution pipe 139 and the lower part of the absorber 111, and the bypass pipe 141 is provided with a concentrated solution bypass valve 143. Concentrate bypass valve 1
When 43 is opened, the concentrated solution tube 139 is connected to the absorber 1
The concentrated liquid is supplied to a lower part of the liquid supply 11, and the supply of the concentrated liquid is stopped by closing the concentrated liquid bypass valve 143. Also, the refrigerant distributor 134
And a concentrated solution pipe 139 are connected by a conduit 147. A refrigerant freezing prevention valve 145 is provided in the middle of the conduit 147. When the refrigerant freezing prevention valve 145 is opened, the concentrated liquid is supplied to the refrigerant distributor 134 from the concentrated solution pipe 139, and the supply of the concentrated liquid is stopped by closing the refrigerant freezing prevention valve 145. Further, the refrigerant distributor 134 is provided with a refrigerant temperature sensor 149 for detecting a refrigerant temperature, and a detection signal from the refrigerant temperature sensor 149 is input to the control device 151. The controller 151 determines that the temperature based on the detection signal from the refrigerant temperature sensor 149 has three criteria (FIG. 7).
Where the concentrated liquid bypass valve 1 is located.
4 3, the refrigerant antifreezing valve 145 or solution pump 113,
, Etc., respectively.

FIG. 7 is an explanatory view of a standard for controlling the operation of the concentrated liquid bypass valve, the refrigerant freezing prevention valve, and the solution pump according to the evaporator refrigerant temperature. FIG. FIG. 7 (b) shows the temperature reference for control, the temperature reference for opening / closing control of the refrigerant freezing prevention valve, and FIG. 7 (c) shows the temperature reference for operation control of a refrigerator such as a solution pump. FIG. 8 is a time chart for explaining the operation of the conventional control system. FIG. 9 is a flowchart for explaining the operation of the conventional control system.

First, when the cooling operation is turned on (ON) (step S900), the control unit 151 immediately checks the temperature based on the detection signal from the refrigerant temperature sensor 149 in accordance with the operation standard of FIG. Step S
901). Here, when the controller 151 detects that the temperature is equal to or higher than 3 [degrees C] (step S90).
1; ON), the controller 151 sends the concentrated liquid bypass valve 143
And a command to close the refrigerant freezing prevention valve 145 is output, and the combustion of a burner (not shown) is started (step S
902), and returns to the temperature determination (step S901) based on the operation reference of FIG. 7A again. Then, at time t in FIG.
In the period from 80 to t83, the processing of the above-described temperature determination (step S901) and the output of a command to close the concentrated liquid bypass valve 143 and the refrigerant freezing prevention valve 145 to continue combustion (step S902) are repeated. .

These processes (steps S901 and S90)
As 2) is continued, the temperature of the solution from the high-temperature regenerator 119 gradually increases. This detected temperature is input to the controller 151 by a sensor (not shown),
When the temperature reaches, for example, 122 [degree C] at 81, the controller 151
, The solution pump 113 is operated, and the solution pump 113 is turned on and off until the temperature is stabilized. Then, when the solution temperature from the high-temperature regenerator 119 is stabilized (time t82), the solution pump 113 is operated continuously.

Thus, a solution circulation cycle of the absorption chiller / heater is formed. Then, in the case where the temperature of the cooling water flowing through the absorption cooling pipe 127 is low and the operation is in a state of having an absorbing power,
At time t83, the controller 151 determines that the refrigerant temperature based on the detection signal from the refrigerant temperature sensor 149 is, for example, 2
When the temperature falls below [degree C], it is detected based on the operation standard of FIG. 7A (step S901; OFF), and the controller 151 issues a valve opening command to the concentrated liquid bypass valve 143 (step S901). S903). As a result, the concentrated liquid bypass valve 143 is opened. The controller 151 that has output this command immediately determines again whether the refrigerant temperature based on the detection signal from the refrigerant temperature sensor 149 is 1 [° C.] or less, as shown in FIG.
Judgment is made in light of the operation standard of (b) (step S90)
4) When it is determined that the difference is not less than 1 [degree C] (step S904; ON), a command to close the refrigerant freezing prevention valve 145 is issued and a combustion continuation command is output (step S905) . The process returns to the determination of the temperature based on the operation reference (a) (step S901). Time t8 in FIG.
During the period from 3 to t84, the control device 151 determines in step S90
The processing of 1-S903-S904-S905-S901 is repeated.

The control unit 151 executes steps S901-S9.
While the process of 03-S904-S905-S901 is repeated, when the time t84 in FIG.
For example, when the refrigerant temperature according to the detection signal from 49 is 1 [degree C].
When the controller 151 detects that the following has been reached (step S904; OFF), the controller 151 returns to FIG.
A valve opening instruction is output to the refrigerant anti-freezing valve 145 in light of the operation standard of (b) (step S906). As a result, the refrigerant freezing prevention valve 145 is opened, and the concentrated liquid is supplied from the concentrated solution pipe 139 to the refrigerant distributor 134. Can be continued.

The controller 151 determines that the refrigerant temperature based on the detection signal from the refrigerant temperature sensor 149 is, for example, −2.
[Degree C] It is determined whether or not the following has been reached (Step S)
907). If the controller 151 determines that the refrigerant temperature is not −2 ° C. (Step S900; O)
N), the combustion is continued (step S908), and FIG.
(A) Determination of refrigerant temperature based on operation standard (step S
Return to 901). Until the time t85 in FIG. 8 is reached, the control device 151 executes steps S901-S903-S90.
The processing of 4-S906-S907-S908-S901 is repeated.

When this process is repeated, the coolant temperature is low or the cooling load is small, and the coolant temperature further decreases. When the time reaches t85 in FIG. 8, a detection signal from the coolant temperature sensor 149 is output. When the controller 151 detects that the refrigerant temperature has reached −2 ° C. (step S907; OFF), the combustion and solution pump 113 are stopped for safety (step S90).
9).

As described above, the conventional control system described above operates. And in the control system described above,
When the refrigerating operation is started from a state where the cooling water temperature is extremely low as in the case of winter cooling, the control device 151 executes the above-described flowchart of FIG. 9 and executes the same processing as described above, but immediately executes step S901. -S903
-S904-S906-S907-S909-S901
Is performed, the combustion is stopped, and the operation of the solution pump 113 is stopped (step S909), and it is difficult to return.

[0016]

As described above, the combustion is stopped and the operation of the solution pump 113 is stopped (step S909).
Has been executed, the only way to return to operation is to guide the concentrated liquid having a high temperature from the refrigerant freezing valve to the refrigerant distributor 134 to raise the refrigerant temperature, but in the conventional control system described above, When the cooling operation is stopped, the solution pump 113
Is stopped and the solution flow rate is small at the start of operation, since the concentrated solution bypass valve 143 is open, all the concentrated solution is bypassed, and even if the refrigerant freeze prevention valve 145 is opened, the concentrated solution bypass valve 145 is opened. There was a drawback that the liquid could not be guided to the refrigerant distributor 134 and the operation could not be restored.

In view of the above, it is an object of the present invention to provide a cooling control method and apparatus for an absorption chiller / heater which enables a cooling operation even when the cooling water temperature is low.

[0018]

In order to achieve the above object, a cooling control method for an absorption chiller / heater according to the present invention comprises introducing a solution of an absorber to a regenerator by a solution pump and heating the solution by the regenerator. The heated solution is separated into a refrigerant vapor and a concentrated liquid, and the concentrated liquid is guided to the absorber, while the refrigerant vapor is guided to the condenser to liquefy, and the liquefied refrigerant is guided to the evaporator to evaporate. In the cooling control method of the absorption refrigerator in which the solution is absorbed by the absorber, during cooling of the absorption chiller / heater, the concentrated solution is bypassed to a lower portion of the absorber until the cooling water temperature reaches a predetermined temperature. Is what you do.

Further, in order to achieve the same object, a cooling control device for an absorption chiller / heater according to the present invention comprises: introducing a solution in an absorber to a regenerator by a solution pump; heating the solution by the regenerator; From the refrigerant vapor and the concentrated liquid, the concentrated liquid is guided into the absorber, the refrigerant vapor is guided to the condenser and liquefied, and the liquefied refrigerant is guided to the evaporator to evaporate. An absorption refrigerator that absorbs the solution in the absorber, a concentrated liquid bypass valve provided in a bypass pipe that bypasses the concentrated liquid below the absorber, and a conduit that guides the concentrated liquid to a refrigerant distributor in the evaporator. A refrigerant freezing prevention valve provided, a refrigerant temperature sensor for detecting a refrigerant temperature in the evaporator, and control for controlling opening and closing of the concentrated liquid bypass valve and the refrigerant freezing prevention valve according to the temperature detected by the refrigerant temperature sensor. Cooling of absorption chiller / heater consisting of equipment The control device includes a cooling water temperature detection sensor that detects a cooling water temperature, and a bypass unit that bypasses all the concentrated solution to be sent to the concentrated liquid distributor of the absorber by a bypass command to a lower portion of the absorber, and the control device includes: A cooling water temperature signal from a cooling water temperature detection sensor is compared with a predetermined reference value, and a bypass command can be output to the bypass means when the cooling water temperature signal is lower than a predetermined reference value. It is characterized by the following.

[0020]

According to the cooling control method of the absorption chiller / heater, attention is paid to the fact that the temperature of the cooling water is increased by the heat input to the absorption chiller / heater, and until the cooling water reaches a predetermined temperature. The solution is circulated between the absorber and the high temperature regenerator,
After the cooling water temperature reaches a predetermined temperature, the operation returns to the original cooling operation.

In the cooling control device for the absorption chiller / heater, a cooling water temperature sensor for detecting the temperature of the cooling water is provided, focusing on the fact that the temperature of the cooling water rises as the heat enters the absorption chiller / heater. In addition to the above, a bypass means for returning all the solution to the lower part of the absorber is provided, and a command to open the bypass means is issued from the control device until the temperature according to the detection signal from the cooling water temperature detection sensor reaches a predetermined value. By outputting, the above method can be realized.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

FIG. 1 is a system diagram showing an embodiment of an absorption chiller / heater and its cooling control device of the present invention.

In FIG. 1, the lower part of the absorber 1 is connected to the suction side of the solution pump 3, and the discharge side of the solution pump 3 is connected to the high temperature regenerator 9 via the low temperature heat exchanger 5 and the high temperature heat exchanger 7. The dilute solution in the absorber 1 is pressurized by the solution pump 3 and is connected to the low-temperature heat exchanger 5 and the high-temperature heat exchanger 7.
After the heat exchange in step (1), the heat is supplied to the high temperature regenerator (9). The high-temperature regenerator 9 is connected to the separator 11, and a solution heated by a burner (not shown) in the high-temperature regenerator 9 enters the separator 11 and is separated into refrigerant vapor and a primary concentrated solution by the separator 11. It is to be done. Separator 11
Is connected to the low-temperature regenerator 13 through the high-temperature heat exchanger 7, and heat-exchanges the primary concentrated solution separated by the separator 11 with the dilute solution in the high-temperature heat exchanger 7, and then supplies the solution to the low-temperature regenerator 13. It is to be done. Further, the low-temperature regenerator 13 is connected to a concentrated liquid distributor 14 provided above the inside of the absorber 11 via the low-temperature heat exchanger 5, and the concentrated liquid concentrated in the low-temperature regenerator 13 is subjected to low-temperature heat exchange. After the heat exchange in the vessel 5, the heat is supplied to the concentrated liquid distributor 14. The concentrated liquid is distributed and dropped on the surface of the cooling pipe 17 by the concentrated liquid distributor 14. The concentrated liquid absorbs the refrigerant vapor while flowing down the surface of the cooling pipe 17. The absorption heat generated at this time is removed by the cooling water flowing through the cooling pipe 17.

The separator 11 is connected to a condenser 15 via a low-temperature regenerator 13, guides the refrigerant vapor generated in the separator 11 to the low-temperature regenerator 13, and converts the primary concentrated solution into the low-temperature regenerator 13. After being heated again, it is guided to the condenser 15. The upper part of the low-temperature regenerator 13 is provided with a condenser 15.
The vapor generated from the primary concentrated solution in the low-temperature regenerator 13 is also led to the condenser 15. Inside the condenser 15, a condensation cooling pipe 19 is provided.
The refrigerant vapor exchanges heat with the cooling water flowing through the condensing cooling pipe 19 to remove heat of condensation, whereby the refrigerant vapor is cooled and condensed and liquefied. The condenser 15 is an evaporator 23
And a refrigerant liquid liquefied in the condenser 15 is supplied to the refrigerant distributor 24 in the evaporator 23. This refrigerant liquid is supplied to the refrigerant distributor 24.
As a result, the water is sprayed on the evaporator heat transfer tubes 25 and evaporates, and the water flowing through the evaporator heat transfer tubes 25 is deprived of latent heat of evaporation. This allows
Cold water 27 can be obtained from the evaporator heat transfer tube 25, and cooling or the like can be performed using the cold water 27.

On the other hand, in FIG. 1, the control system for controlling the temperature of the evaporator refrigerant in order to avoid freezing of the refrigerant and crystallization of the solution is constructed as follows. That is, the concentrated solution pipe 39 is communicated with the lower part of the absorber 1 by the bypass pipe 41, and the bypass pipe 41 is provided with the concentrated solution bypass valve 43. When the concentrated liquid bypass valve 43 is opened, the concentrated liquid is supplied from the concentrated liquid pipe 39 to the lower part of the absorber 1, and the supply of the concentrated liquid is stopped by closing the concentrated liquid bypass valve 43. The refrigerant distributor 24 and the concentrated solution pipe 39 communicate with each other via a conduit 47, and a refrigerant freezing prevention valve 45 is provided in the conduit 47. Refrigerant freezing prevention valve 45
Is opened, the concentrated liquid is supplied from the concentrated solution pipe 39 to the refrigerant distributor 24, and the supply of the concentrated liquid is stopped by closing the refrigerant freezing prevention valve 45. The refrigerant distributor 24 is provided with a refrigerant temperature sensor 49 for detecting a refrigerant temperature, and a detection signal from the refrigerant temperature sensor 49 is transmitted to the control device 51.
Has been entered. Further, a bypass means 53 is connected between the concentrated solution pipe 39 and the absorber 1, and all the solution in the concentrated solution pipe 39 is supplied to a lower portion of the absorber 1 by a bypass command of the bypass means 53, or is closed. Solution is not supplied by command. This bypass means 5
Reference numeral 3 denotes a pipe 55 for communicating the concentrated solution pipe 39 with the lower part of the absorber 1, and a full concentrated liquid bypass valve 57 provided in the middle of the pipe 55. Further, a cooling water temperature detection sensor 59 that can detect the temperature of the cooling water is provided in a pipe portion supplied to the cooling pipe 17. Detection signals from the refrigerant temperature sensor 49 and the cooling water temperature detection sensor 59 are input to the control device 51. The control device 51 opens and closes the full concentrated liquid bypass valve 57 of the bypass means 53 depending on where the temperature based on the detection signal from the cooling water temperature detection sensor 59 falls within one operation standard (see FIG. 3A). The concentrated liquid bypass valve 4 is controlled, depending on where the temperature based on the detection signal from the refrigerant temperature sensor 49 falls within the three criteria (see FIGS. 3B to 3D).
1. The drive control of the refrigerant freezing prevention valve 45, the solution pump 3, and the like can be performed.

FIG. 2 is a block diagram showing a detailed configuration of the control device. The control device 51 includes a central processing unit (CPU) 511 integrating a processing device and a storage device, and
A sensor input unit 512 for inputting data to U511,
And an output unit 513 for outputting a command from the CPU 511. When the detection signal from the refrigerant temperature sensor 49 and the detection signal from the cooling water temperature detection sensor 59 are supplied to the sensor input unit 512, they are converted into digital signals at the sensor input unit 512 and supplied to the sensor input unit 512. Further, the CPU 511 forms a drive command based on the detection signal from the sensor and the driving reference in FIGS. 3A to 3D as described above, and outputs the command to the output unit 5.
Via 13, output is made to the all concentrated liquid bypass valve 57, the concentrated liquid bypass valve 43, the refrigerant freezing prevention valve 45, the solution pump 3 (burner operation) and the like.

An embodiment constructed as described above will be described below with reference to FIGS. 1 and 2 and FIGS.

FIGS. 3A and 3B are explanatory diagrams showing the above-mentioned operation standards. FIG. 3A shows the operation standard of the full concentrated liquid bypass valve 57, and FIG. 3 (c) shows the operating standards of the refrigerant freezing prevention valve 45. In each figure, the horizontal axis represents temperature, and the vertical axis represents opening / closing or on / off operation. In FIG. 3, the reference temperature is different between when the temperature rises and when the temperature falls. This is to prevent hunting.

FIG. 4 is a time chart for explaining the operation of the embodiment of the present invention. FIG. 5 is a flowchart for explaining the operation of the embodiment.

First, when the cooling operation is turned on (time t10 in FIG. 4, step S500), a detection signal from the cooling water temperature detection sensor 59 is taken into the control device 51. The controller 51 determines that the temperature based on the detection signal from the cooling water temperature detection sensor 59 is equal to or lower than the reference value T1 (see FIG. 3A,
At time t10 in FIG. 4, step S501; OFF), a command to open all the concentrated liquid bypass valve 57 of the bypass means 53 (step S502) and close the concentrated liquid bypass valve 43 and the refrigerant freezing prevention valve 45 is output and shown. Burning of the burner not to be started is started (step S503), and the process returns to step S501 again. The control device 51 operates at time t in FIG.
This processing is repeated during the period from 10 to tT1 (steps S501 to S503).

These processes (steps S501 to S50)
As 3) is continued, the temperature of the solution from the high-temperature regenerator 9 gradually increases (time t10 to t11 in FIG. 4). The detected temperature is input to the control device 51 by a sensor (not shown). When the temperature reaches, for example, 122 [degrees C] at time t11, the solution pump 3 is operated by the control device 51.
The solution pump 3 is turned on and off until the temperature is stabilized (time t11 to t12 in FIG. 4). And the high temperature regenerator 9
After the time when the solution temperature from
~), The solution pump 3 is operated continuously. Time t in FIG.
During the period from 12 to tT1, the control device 51 repeatedly executes the processing of the flowchart shown in FIG. 5 (steps S501 to S503). As a result, since the absorption in the absorber 1 is almost eliminated, the temperature does not decrease due to the detection signal from the refrigerant temperature sensor 49, and the cooling operation is performed.

Here, there is no heat radiation in the absorber 1, but
In the condenser 15, heat is released by condensation of the refrigerant vapor, so that the temperature of the cooling water flowing through the condensation cooling pipe 19 increases. Then, when the control device 51 detects at time tT1 that the temperature detected by the detection signal from the coolant temperature detection sensor 59 has risen above the reference temperature T1 of the operation reference in FIG. 3A (step S501; ON). ,
A command to close the all concentrated liquid bypass valve 57 of the bypass means 53 is output from the control device 51 (step S504).
As a result, the all concentrated liquid bypass valve 57 is closed.

Then, the control device 51 immediately checks the temperature based on the detection signal from the refrigerant temperature sensor 49 with reference to the operation reference of FIG. 3B (step S505).
Here, if the temperature is 3 [degrees C] or more, the controller 5
1 (step S505; ON), the controller 51 outputs a command to close the concentrated liquid bypass valve 43 and the refrigerant freezing prevention valve 45, and continues to burn a burner (not shown) (step S506). 3
(A) Temperature determination based on the operation standard (step S50)
Return to 1).

These processes (steps S501 and S50)
4, S505 and S506) continue at time t13.
In step S505, when the controller 51 detects that the refrigerant temperature based on the detection signal from the refrigerant temperature sensor 49 has become, for example, 2 [deg.] C. or less, based on the operation reference in FIG. 3B (step S505; OFF), The control device 51 issues a valve opening command to the concentrated liquid bypass valve 43 (step S507). Thereby, the concentrated liquid bypass valve 43 is opened. As a result, the absorption capacity of the absorber 1 decreases.

In such a state, the control device 51 determines again whether the refrigerant temperature based on the detection signal from the refrigerant temperature sensor 49 is 1 [° C.] or less, based on the operation standard shown in FIG. (S508), when it is determined that the difference is not less than 1 degree C (step S508; ON), the refrigerant freeze prevention valve 45 is continuously output with the closing command and the combustion continuation command is output (step S509). , Again determining the temperature based on the operation standard of FIG.
Return to 501). During the period from time t13 to time t14 in FIG. 4, the control device 51 executes steps S501-S504-S505-S
The processing of 507-S508-S509-S501 is repeated.

Although the absorption capacity of the absorber 1 has been reduced in this way, the temperature based on the detection signal from the refrigerant temperature sensor 49 is 1 [degree C] of the operation reference of FIG.
When the following is reached ((time t14 in FIG. 3, step S
508; OFF), a command to open the refrigerant freeze prevention valve 45 is output from the control device 51 (step S51).
0). As a result, the refrigerant freeze prevention valve 45 is opened, and the concentrated liquid is supplied to the refrigerant distributor 24 through the conduit 47. Next, the control device 51 determines whether or not the refrigerant temperature based on the detection signal from the refrigerant temperature sensor 49 has become equal to or lower than −2 [° C.] (step S511).
Since it is not less than 2 [degree C] (step S51)
1; ON) to continue combustion (step S512),
The process returns to the determination of the temperature based on the operation reference of FIG. 3A (step S501). The period from time t14 to t15 in FIG.
The control device 51 performs steps S501-S504-S505.
-S507-S508-S510-S511-S512
-The process of S501 is repeated.

The above processing (steps S501-S504)
-S505-S507-S508-S510-S511
-S512-S501), the refrigerant temperature sensor 4
Assuming that the temperature based on the detection signal from FIG. 9 reaches, for example, 2 [degrees C] in FIG. 3C (time t15 in FIG. 4, step S508; ON), the control device 51 issues a command to close the refrigerant freezing prevention valve 45. And a command to continue combustion is output (step S509), and the process returns to the temperature determination (step S501) based on the operation reference of FIG. 3A. Further, during the period from time t15 to time t16 in FIG. 4, the control device 51 performs steps S501-S504-S505-S507-S5.
The processing of 08-S509-S501 is repeated.

The above processing (steps S501-S504)
-S505-S507-S508-S509-S50
Assuming that the temperature based on the detection signal from the refrigerant temperature sensor 49 reaches, for example, 3 [degree C] in FIG. 3B in the course of 1) (time t16 in FIG. 4, step S505; O).
N), the control device 51 outputs a command to close the refrigerant anti-freeze valve 45 and the concentrated liquid bypass valve 43 and outputs a command to continue combustion (step S506), and again sets the temperature based on the operation standard in FIG. The procedure returns to the determination (step S501).

Thereafter, the operation shifts to the normal cooling operation.

The embodiment of the present invention operates as described above, and can reliably start the cooling operation even when the temperature of the cooling water is low.

In the above-described embodiment, a closed system using a cooling tower is applied to the cooling water, and the cooling water temperature detection sensor 59 is provided at the inlet of the cooling pipe 17. However, in the case of such a closed system, May be any department that can detect the temperature of cooling water.

[0043]

As described above, according to the cooling control method of the absorption chiller / heater of the present invention, even when the temperature of the cooling water is low, the operation is stopped and the generation of the crystallization of the refrigerant liquid is eliminated, so that the smoothing is achieved. There is an effect that a proper cooling operation can be started.

Further, according to the cooling control device of the absorption chiller / heater of the present invention, even when the temperature of the cooling water is low, the operation is stopped and the crystallization of the refrigerant liquid is eliminated, so that the cooling operation can be smoothly started. There is an effect that can be raised.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of a cooling control device for an absorption chiller / heater of the present invention.

FIG. 2 is a block diagram showing a configuration of a control device used in the embodiment.

FIG. 3 is an explanatory diagram of an operation standard used in the embodiment of the cooling control device for the absorption chiller / heater.

FIG. 4 is a timing chart for explaining an embodiment of the cooling control method for the absorption chiller / heater of the present invention.

FIG. 5 is a flowchart for explaining an embodiment of a cooling control method for the absorption chiller / heater.

FIG. 6 is a system diagram of a conventional cooling control device for an absorption chiller / heater.

FIG. 7 is an explanatory diagram of an operation standard used in a conventional device.

FIG. 8 is a timing chart for explaining the operation of the conventional device.

FIG. 9 is a flowchart for explaining the operation of the conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Absorber 3 Solution pump 5 Low temperature heat exchanger 7 High temperature heat exchanger 9 High temperature regenerator 11 Separator 13 Low temperature regenerator 15 Condenser 17 Cooling pipe 19 Condensing cooling pipe 23 Condenser 25 Evaporator heat transfer pipe 39 Concentrated solution pipe 41 Bypass pipe 43 concentrated liquid bypass valve 45 refrigerant freezing prevention valve 47 conduit 49 refrigerant temperature sensor 51 controller 53 bypass means 55 piping 57 full concentrated liquid bypass valve 59 cooling water temperature detection sensor

Claims (1)

(57) [Claims] 1. A solution in an absorber is guided to a regenerator by a solution pump, the solution is heated by the regenerator, separated from the heated solution into refrigerant vapor and a concentrated liquid, and the concentrated liquid is guided to the absorber, and the refrigerant vapor is condensed. To a condenser, liquefy the refrigerant, guide the liquefied refrigerant to an evaporator to evaporate, and absorb the refrigerant vapor into the solution in the absorber, and bypass the concentrated liquid to the lower part of the absorber A concentrated liquid bypass valve provided in a bypass pipe to be provided, a refrigerant freezing prevention valve provided in a conduit for guiding the concentrated liquid to a refrigerant distributor in an evaporator, a refrigerant temperature sensor for detecting a refrigerant temperature in the evaporator, A cooling control device for the absorption chiller / heater comprising: a controller for controlling the opening and closing of the concentrated liquid bypass valve and the refrigerant freezing prevention valve in accordance with the temperature detected by the refrigerant temperature sensor; Detection sensor and A bypass means for causing all the concentrated solution to be sent to the concentrated liquid distributor of the absorber by a pass command to be bypassed at a lower portion of the absorber, wherein the control device transmits a cooling water temperature signal from a cooling water temperature detection sensor to a predetermined reference A cooling control device for an absorption chiller / heater, wherein a bypass command can be output to the bypass means when the cooling water temperature signal is lower than a predetermined reference value.