JPH06159849A - Absorption-type cold/hot water feeder and its controlling method - Google Patents

Abstract

PURPOSE:To prevent a regenerator from being abnormally raised at the low cost without damaging the regenerator by preventing disagreement in correlations between cooling water inlet temperature an generation of freezing of a refrigerant pipe from being produced with high reliability with simplified control and without use of a prior art antifreezing heater. CONSTITUTION:A cooling water inlet temperature sensor 11 detects temperature of cooling water (cooling water inlet temperature) flowing through an inlet of an absorber 5 of a cooling water pipe 12. Control means judges whether or not the cooling water inlet temperature is 8 deg.C or higher, and when the temperature is lower than 8 deg.C, it does not start heating of a soution in a high temperature regenerator 1 by a burner 10 and hence not start cooling operation. The control means judges, when the temperature is 8 deg.C or higher, whether or not the cooling water inlet temperature keeps 2.5 deg.C or higher over past 24 hours, and when the temperature does not keep that temperature, it does not start heating of the solution in the high temperature regenerator 1 and hence does not start the cooling operation.

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 a method of controlling the absorption chiller-heater without damaging the regenerator.

[0002]

2. Description of the Related Art Below, an outline of an example of an absorption chiller-heater will be described with reference to FIGS. FIG. 3 is a diagram for explaining a schematic structure of an example of a double-effect absorption chiller-heater used for air conditioning, in which a refrigerant, a solution, and a cooling during cooling operation among respective members of the double-effect absorption chiller-heater are performed. The flow of water etc. is shown by the arrow. In the figure, the high temperature regenerator 1 has a combustion chamber housed therein, and the burner 10 heats a dilute solution that has absorbed the refrigerant and has a low concentration, and produces a refrigerant vapor from the dilute solution. This refrigerant vapor is sent to the low temperature regenerator 2, and the intermediate concentrated solution which has generated a refrigerant vapor and has a high concentration is sent to the high temperature heat exchanger 8. The low-temperature regenerator 2 reheats the intermediate concentrated solution whose temperature has been lowered by the high-temperature heat exchanger 8 with the refrigerant vapor sent from the high-temperature regenerator 1, and further generates the refrigerant vapor from the intermediate concentrated solution. The intermediate concentrated solution itself is made into a concentrated solution while being sent to the condenser 3, and at the same time, the refrigerant vapor coming from the high temperature regenerator 1 is partially condensed to be a refrigerant liquid and sent to the condenser 3. The condenser 3 uses the cooling water to cool and liquefy the refrigerant vapor generated in the low temperature regenerator 2 and the refrigerant vapor not converted into the refrigerant liquid in the low temperature regenerator 2 into the refrigerant liquid, and then to the evaporator 4 via the refrigerant pipe 13. Send in. The evaporator 4 is provided with a heat transfer tube (cooler) 14 through which circulating water to be cooled flows, and the refrigerant liquid sent from the condenser 3 is sprayed to the heat transfer tube 14 using a sprayer (not shown). The circulating water is cooled to cool water by utilizing the heat of vaporization when the refrigerant liquid becomes refrigerant vapor. In the absorber 5, the concentrated solution that has passed through the low temperature heat exchanger 7 from the low temperature regenerator 2 is introduced and sprayed using a sprayer (not shown) provided in the upper portion.
The concentrated solution, which is dropped, absorbs the vaporized refrigerant vapor in the evaporator 4. A high vacuum is secured in the evaporator 4 by the absorbing action of the absorber 5, and the refrigerant liquid sprinkled on the heat transfer tubes 14 in the evaporator 4 can be immediately evaporated. Further, the absorber 5 is provided with cooling means 15 for cooling when the concentrated solution absorbs the refrigerant vapor and becomes a diluted solution. The cooling means 15 is composed of a coiled pipe, and cooling water is introduced through the cooling water pipe 12. Also,
The cooling means 15 is also connected to the cooling means 16 in the condenser 3 so that cooling water circulates inside.
The high temperature heat exchanger 8 performs heat exchange between the high temperature intermediate concentrated solution and the low temperature diluted solution, and the low temperature heat exchanger 7 performs heat exchange between the high temperature concentrated solution and the low temperature diluted solution. Two stages are provided on the high temperature side and the low temperature side to improve the heat exchange efficiency. The solution circulation pump 6 absorbs the refrigerant vapor in the absorber 5 to form a dilute solution, and the low temperature heat exchanger 7 and the high temperature heat exchanger 8
It is provided for sending to the high temperature regenerator 1 via the and recirculating. During heating operation, generally, a cooling / heating switching valve (not shown) directly introduces the high-temperature refrigerant vapor from the high-temperature regenerator 1 into the evaporator 4 and exchanges heat with the circulating water through the heat transfer pipe 14 to obtain hot water.

The cooling water inlet temperature sensor 11, the control device 9, etc. are used to control the burner 10 during the cooling operation when the outside air temperature is low, such as during the intermediate period (winter, etc.) of the double-effect absorption chiller-heater as described above. Is done by. This control is shown in FIG.
Refer also to the explanation. FIG. 4 is a diagram showing an example of such control. In this control, first, after the cooling operation is started, the cooling water inlet temperature sensor 11 is used to absorb the absorber 5 of the cooling water pipe 12.
The temperature of the cooling water flowing through the entrance to the control unit 9 is detected, and the control device 9 judges whether the temperature is 8 ° C. or higher.
If the temperature is lower than ° C, the burner 10 is turned off and a display device (not shown) indicates that the cooling operation cannot be started. When the temperature is 8 ° C. or higher, the burner 10 is turned on to start the cooling operation.

The cooling water pipe 12 performs such control.
The temperature of the cooling water flowing through the entrance to the absorber 5 is 8 ° C.
This is because when the temperature is below the range, the refrigerant remaining in the refrigerant pipe 13 is likely to be frozen and blocked due to the low outside air temperature. That is, when the refrigerant pipe 13 is closed, the refrigerant is cooled by the condenser 3
And the solution concentration in the system rises, causing an abnormal temperature rise in the high temperature regenerator 1. When such an abnormal temperature rise is detected by a sensor (not shown), a protection switch (not shown) is activated to stop the cooling operation.

[0005]

However, if such an abnormal temperature rise is repeated, the high temperature regenerator 1 may be damaged and cause a leak. Therefore, it is necessary to prevent the stop of the cooling operation for the purpose of cooling or the like due to the operation of the protection switch (not shown) as much as possible. For example, as described above, the temperature of the cooling water flowing through the inlet of the cooling water pipe 12 to the absorber 5 Refrigerant pipe 13
Is often frozen, and it is not possible to sufficiently prevent an abnormal temperature rise of the high temperature regenerator 1. This occurs because the presence or absence of freezing of the refrigerant pipe 13 is indirectly detected by detecting the temperature of the cooling water flowing through the inlet of the cooling water pipe 12 to the absorber 5. .
Further, in order to prevent these, as shown in FIG.
It is also attempted to prevent the freezing of the refrigerant pipe 13 by providing a freeze-prevention heater 17 with a thermostat in the, but the operation cost of the freeze-prevention heater 17 is too high, and the cost of cooling operation cannot be reduced. There's a problem.

It is an object of the present invention to provide an absorption chiller-heater and a control method for the absorption chiller-heater that prevent an abnormal temperature rise of the high-temperature regenerator at a low cost and do not damage the high-temperature regenerator. To do.

[0007]

The gist of the present invention for solving the above problems is to introduce cooling water into a absorber for cooling when a concentrated solution absorbs a refrigerant vapor and becomes a dilute solution. A water introducing pipe, cooling water temperature detecting means for detecting a temperature of the cooling water flowing through an inlet portion of the cooling water introducing pipe to the absorber, and a rare gas inside the regenerator in which a concentration is thinned by absorbing a refrigerant. Heating means for heating the solution to generate a refrigerant vapor from the diluted solution; and heating the diluted solution by the heating means when the temperature detected by the cooling water temperature detecting means is lower than a preset first temperature. First control means that does not start the cooling operation by not starting, and the detected temperature is the first temperature when the first control means determines that the detected temperature is equal to or higher than the first temperature. Lower and preset second temperature And a second control unit that does not start the cooling operation by not starting the heating of the dilute solution by the heating unit when it is determined that the temperature has become lower within a preset certain period in the past. It is in an absorption chiller-heater.

The first temperature is set to any temperature in the range of 5 to 10 ° C., and the second temperature is set to any temperature in the range of 1 to 4 ° C. The chiller / heater is also the subject.

Further, the cooling water flowing through the inlet portion of the cooling water introducing pipe for introducing cooling water for cooling into the absorber when the concentrated solution absorbs the refrigerant vapor and becomes a dilute solution. When the temperature detected in the step of detecting the temperature and the step of detecting the temperature of the cooling water is lower than a preset first temperature, the diluted solution in the regenerator that has become thin due to absorption of the refrigerant is diluted. In the step of not starting the cooling operation by not starting the heating of the diluted solution by the heating means for heating and generating the refrigerant vapor from the diluted solution, and in the step of stopping the heating of the diluted solution, the detected temperature is the first It is preset that the detected temperature in the step of detecting the temperature of the cooling water when it is determined to be equal to or higher than the temperature is lower than the preset second temperature and lower than the preset second temperature. Within a certain period in the past When it is determined that Tsu and the control method also subject matter of the absorption chiller-heater having a step that does not set up a cooling operation by not starting the heating of the diluted solution.

The absorption-type cold / hot water having the first temperature set to any temperature in the range of 5 to 10 ° C. and the second temperature set to any temperature in the range of 1 to 4 ° C. The control method of the machine is also a gist.

[0011]

The cooling water temperature detecting means detects the temperature of the cooling water flowing through the inlet of the cooling water introducing pipe to the absorber. When the first control unit determines that the detected temperature is lower than the first temperature, the first control unit does not start heating the dilute solution by the heating unit. Therefore, the cooling operation such as the cooling operation is not started. First
When the second control means determines that the detected temperature is lower than the second temperature within a preset past certain period when it is determined that the temperature is equal to or higher than the temperature of Do not start heating the solution. Therefore, the cooling operation such as the cooling operation is not started.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a schematic structure of a double-effect absorption chiller-heater used for air conditioning according to an embodiment of the absorption chiller-heater of the present invention. The members having the same reference numerals as those in FIG. 3 are the same members as those of the conventional double-effect absorption chiller-heater described with reference to FIG. In the same figure, as in FIG. 3, the flow of the refrigerant, the solution, the cooling water and the like during the cooling operation between the respective members of the double-effect absorption chiller-heater is indicated by arrows. No heater such as the freeze prevention heater 17 of FIG. 3 is provided.

A control device 18 is provided in the double-effect absorption chiller-heater of this embodiment. A microcomputer is incorporated in the control device 18 to perform the following control. FIG. 2 is a diagram showing an example of such control. First,
When the cooling operation is started, the temperature of the cooling water flowing through the inlet of the cooling water pipe 12 to the absorber 5 detected by the cooling water inlet temperature sensor 11 (cooling water inlet temperature) is set to Step 1 as the first preset value. Temperature (8 ° C. in this embodiment) or more is determined, and the temperature is
If the temperature is less than the temperature (8 ° C.), the burner 10 remains OFF and the cooling operation is not started. Also, at this time,
A display device (not shown) displays that the cooling operation cannot be started. The first temperature is preferably set to any temperature in the range of 5 to 10 ° C. Particularly, it is most effective to set the temperature to about 8 ° C. as in this embodiment.

If the temperature is lower than 8 ° C., the process proceeds to Step 2, and the cooling water inlet temperature is preset to be lower than the first temperature within a preset past fixed period (past 24 hours in this embodiment). Further, it is judged whether or not the second temperature (2.5 ° C. in the present embodiment) or more is maintained, and if the temperature is lower than the temperature (2.5 ° C.) even once, the burner 10 is turned off.
Do not start the air-conditioning operation with F left. Further, at this time, a display device (not shown) displays that the start of the cooling operation is impossible. The second temperature is preferably set to any temperature in the range of 1 to 4 ° C. Particularly, it is most effective to set the temperature to about 2.5 ° C. as in this embodiment.

As described above, in addition to the conventional first temperature, the second temperature within a preset past period is a problem because the present control determines whether the refrigerant pipe 13 is frozen or not. This is because it is intended to be detected indirectly by the inlet temperature. That is, even if the current cooling water inlet temperature is about 8 ° C. or higher in Step 1, it can be traced back to the past 24 hours in the past 24 hours, especially in the winter.
There may be a case where the outside air temperature is extremely low within a period of about 4 hours, which may cause the refrigerant pipe 13 to remain frozen. Therefore, even if the current cooling water inlet temperature is about 8 ° C. or higher, if the cooling operation is started and the heating of the solution by the high temperature regenerator 1 is started, the abnormal temperature rise of the high temperature regenerator 1 is increased as described above. As a result, the high temperature regenerator 1 will be damaged.

Therefore, as a result of the present inventor's investigation of the relationship between the outside air temperature, the cooling water, and the freezing of the refrigerant pipe 13, even if the current cooling water inlet temperature is about 8 ° C. or higher, for example, the past 24
Detect whether or not any temperature (especially about 2.5 ° C) in the range of 1 to 4 ° C is traced back about time, and do not start the cooling operation when the temperature is not maintained. Then, it was confirmed that it is possible to prevent with high accuracy a discrepancy in the correlation between the cooling water inlet temperature and the occurrence of freezing of the refrigerant tube 13, which would start the cooling operation even if the refrigerant tube 13 is frozen.

Generally, the object can be sufficiently achieved if the preset fixed period in Step 2 is about 24 hours as in the present embodiment, but the present invention is
The preset fixed period in the past is not limited to 24 hours, but can be set variously such as about 12 hours or about 36 hours.

Next, the operation of the absorption chiller-heater of this embodiment will be briefly described. When the cooling operation is started, the cooling water inlet temperature sensor 11 detects the cooling water inlet temperature. When the controller 18 determines that the detected temperature is lower than the first temperature, the controller 18 does not start the heating of the dilute solution in the high temperature regenerator 1 by the burner 10. As a result, the cooling operation is not started. When it is determined that the detected temperature is equal to or higher than the first temperature, it is determined by the burner 10 that the detected temperature has become lower than the second temperature within a preset past certain period. The heating of the dilute solution in the high temperature regenerator 1 is not started, and the cooling operation is not started. When it is determined that the detected temperature has been maintained at the second temperature or higher within the preset past certain period, heating of the dilute solution in the high temperature regenerator 1 by the burner 10 is started, and the cooling operation is started.

If it is determined that the detected temperature has become lower than the second temperature within a preset past certain period, the burner 10 does not start heating the dilute solution in the high temperature regenerator 1. Therefore, it is possible that the cooling operation cannot be started for a long time. Regarding this point, in Step 1, the temperature does not reach the first temperature, or
When the control device 18 determines that the second temperature or higher cannot be maintained within the past certain period preset in p2, the heating operation is once performed to warm the cooling water, and then the control is switched to the cooling operation. You can solve it by doing.

According to the double-effect absorption type chiller / heater of this embodiment described above, the cooling water inlet temperature and the refrigerant can be controlled by the simple control as described above and without using the conventional antifreezing heater 17. A double-effect absorption-type cold / hot water that can prevent the mismatch of the correlation with the occurrence of freezing of the pipe 13 with high accuracy, can prevent the abnormal temperature rise of the high temperature regenerator 1 at low cost, and does not damage the high temperature regenerator 1. Machine can be provided.

[0021]

According to the control method of the absorption chiller-heater or the absorption chiller-heater of the present invention described above, the inlet of the cooling water introducing pipe to the absorber can be used without using the conventional antifreeze heater. Absorption-type chiller-heater that can prevent the abnormal temperature rise of the regenerator at a low cost by preventing the disagreement of the correlation between the temperature of the cooling water flowing through it and the occurrence of freezing of the refrigerant pipe with high accuracy and preventing damage to the regenerator. Can be provided.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating the configuration of a double-effect absorption-type chiller-heater according to an embodiment of the present invention.

FIG. 2 is a flow chart for explaining the operation of the double-effect absorption chiller-heater according to the embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating the configuration of a conventional double-effect absorption-type chiller-heater.

FIG. 4 is a flowchart for explaining the operation of a conventional double-effect absorption chiller-heater.

[Explanation of symbols]

 1 High Temperature Regenerator 3 Condenser 4 Evaporator 5 Absorber 10 Burner 11 Cooling Water Inlet Temperature Sensor 12 Cooling Water Pipe 13 Refrigerant Pipe 18 Control Device

Claims (4)

[Claims] 1. A cooling water introducing pipe for introducing cooling water into an absorber for cooling when a concentrated solution absorbs a refrigerant vapor to become a dilute solution, and an inlet of the cooling water introducing pipe to the absorber. Cooling water temperature detecting means for detecting the temperature of the cooling water flowing through the part, heating means for heating the dilute solution in the regenerator, which has absorbed the refrigerant and has a low concentration, and for producing the refrigerant vapor from the dilute solution,
First control means for not starting a cooling operation by not starting heating of the dilute solution by the heating means when the temperature detected by the cooling water temperature detection means is lower than a preset first temperature; When the first control means determines that the detected temperature is equal to or higher than the first temperature, the detected temperature is lower than the first temperature and lower than a preset second temperature. An absorption chiller-heater equipped with a second control unit that does not start the cooling operation by not starting the heating of the dilute solution by the heating unit when it is determined that it is within a preset past certain period . 2. The first temperature is set to any temperature in the range of 5 to 10 ° C., and the second temperature is set to any temperature in the range of 1 to 4 ° C. Absorption chiller-heater described. 3. The cooling water flowing through an inlet portion of a cooling water introducing pipe for introducing cooling water for cooling when the concentrated solution absorbs the refrigerant vapor to become a dilute solution into the absorber. When the temperature detected in the step of detecting the temperature and the step of detecting the temperature of the cooling water is lower than a preset first temperature, the diluted solution in the regenerator that has become thin due to absorption of the refrigerant is diluted. In the step of not starting the cooling operation by not starting the heating of the diluted solution by the heating means for heating and generating the refrigerant vapor from the diluted solution, and in the step of stopping the heating of the diluted solution, the detected temperature is the first It is preset that the detected temperature in the step of detecting the temperature of the cooling water when it is determined to be equal to or higher than the temperature is lower than the preset second temperature and lower than the preset second temperature. It was within a certain period in the past When judged, the method for controlling the absorption chiller-heater comprising the step of not starting the cooling operation by not starting the heating of the diluted solution. 4. The third temperature is set to any temperature in the range of 5 to 10 ° C., and the second temperature is set to any temperature in the range of 1 to 4 ° C. A method for controlling the absorption type chiller-heater described.