JP3208472B2 - Absorption chiller / heater and control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller / heater equipped with an evaporator and an absorber, and more particularly to an absorption chiller / heater and an absorption chiller / heater suitable for detecting a decrease in the performance of an evaporator or an absorber. The present invention relates to a water machine control method.

[0002]

2. Description of the Related Art In a conventional absorption chiller / heater, as shown in FIG. 4, a high temperature regenerator 1 for heating a dilute solution, a separator 2 for separating the dilute solution into refrigerant vapor and an intermediate concentrated solution, A high-temperature solution heat exchanger 7 for heat-exchanging the intermediate concentrated solution with the dilute solution to lower the temperature, a low-temperature regenerator 3 for heating the lowered intermediate concentrated solution again by the refrigerant vapor to generate a concentrated solution, and a dilute solution for the concentrated solution. A low-temperature solution heat exchanger 8 for performing heat exchange to lower the temperature, a condenser 4 for condensing refrigerant vapor into a liquid refrigerant with cooling water, an evaporator 5 for evaporating the liquid refrigerant to generate cold water, and Absorber 6 that absorbs and cools with cooling water sent to condenser 4 to generate a dilute solution, and solution circulation pump 9 that sends the dilute solution to high-temperature regenerator 1 through respective heat exchangers 7 and 8.
This is a configuration including:

The operation of the absorption chiller / heater during normal cooling operation will be described. The dilute solution in the high-temperature regenerator 1 is heated by a heating source, rises in a gas-liquid two-phase state, and flows into the separator 2. Separator 2
The dilute solution in a gas-liquid two-phase state flowing into the condenser is separated into a refrigerant vapor and an intermediate concentrated solution, and the refrigerant vapor flows into the condenser 4 through a refrigerant vapor coil provided in the low-temperature regenerator 3, and the intermediate concentrated solution It flows into the heating fluid side of the high-temperature solution heat exchanger 7. The intermediate concentrated solution that has flowed into the high-temperature solution heat exchanger 7 passes through the high-temperature solution heat exchanger 7 and flows into the low-temperature regenerator 3 while heating the dilute solution flowing on the heated fluid side, and is dispersed on the refrigerant vapor coil. Is done. The refrigerant vapor flowing in the refrigerant vapor coil heats the surrounding intermediate concentrated solution to evaporate the refrigerant to generate a secondary refrigerant vapor, which is cooled and condensed to form a gas-liquid two-phase condenser 4.
Flows into. The secondary refrigerant vapor generated by the low-temperature regenerator 3 also flows into the condenser 4, and is cooled and condensed by the cooling water flowing in the cooling water coil together with the refrigerant flowing through the refrigerant vapor coil to become a liquid refrigerant.

The liquid refrigerant generated in the condenser 4 is supplied to the evaporator 5
And is spread on an evaporator coil provided in the evaporator 5, evaporates by removing the heat of the heat medium (cold water) flowing through the evaporator coil, and turns into refrigerant vapor again. Flows into. The heat medium deprived of heat and cooled is led to a cooling load, and after cooling, returns to the evaporation coil again. The intermediate concentrated solution obtained by evaporating the refrigerant as the secondary refrigerant vapor in the low-temperature regenerator 3 becomes a concentrated solution, and flows into the heating fluid side of the low-temperature solution heat exchanger 8. The concentrated solution flowing into the low-temperature solution heat exchanger 8 passes through the low-temperature solution heat exchanger 8 while heating the dilute solution flowing on the heated fluid side, and flows into the absorber 6. The concentrated solution that has flowed into the absorber 6 is sprayed on the cooling water coil and absorbs the refrigerant vapor flowing from the evaporator 5 to become a dilute solution. The heat of absorption generated when the concentrated solution absorbs the refrigerant vapor is transferred to the cooling water flowing in the cooling water coil, and is carried to the cooling tower. Then, the absorbed heat of absorption and heat of condensation are released to the atmosphere.

[0005] The dilute solution generated in the absorber 6 is sucked into a solution circulation pump 9, pressurized, and flows into the heated fluid side of the low-temperature solution heat exchanger 8. The diluted solution flowing into the low-temperature solution heat exchanger 8 passes through the low-temperature solution heat exchanger 8 while being heated by the concentrated solution flowing on the heating fluid side, and flows into the heated fluid side of the high-temperature solution heat exchanger 7. The dilute solution flowing into the high-temperature solution heat exchanger 7 passes through the high-temperature solution heat exchanger 7 while being heated by the intermediate concentrated solution flowing on the heating fluid side, and flows into the high-temperature regenerator 1. The dilute solution flowing into the high temperature regenerator 1 repeats the above cycle again.

[0006] Therefore, in the cooling operation, if the capacity is reduced due to the absorber and the evaporator, the state cannot be sensed by the conventional technology, and the cooling becomes ineffective due to an increase in the room temperature due to an increase in the temperature of the chilled water. For the first time, it is sensed in the form of a claim. When the performance of the absorber is reduced, the evaporator temperature rises because the absorption performance is reduced, and when the performance of the evaporator is reduced, the refrigerant is hardly evaporated due to poor wettability of the evaporator heat transfer tube. As a result, the ability to generate cold water is reduced, and the cooling capacity is reduced. When the performance of the evaporator is reduced, if the absorber is normal, the temperature of the evaporator on the evaporation side of the evaporator will be lower than in the normal state because of the absorption performance. On the other hand, since the evaporator temperature fluctuates greatly depending on the cooling water temperature, the amount of refrigerant stored in the refrigerant storage chamber is adjusted, and the solution concentration is adjusted to cope with the fluctuation of the cooling water temperature. Alternatively, if the performance is reduced due to the evaporator, cooling becomes ineffective and the overload operation is repeated.

[0007]

In the conventional absorption chiller / heater, since the temperature of the evaporator greatly varies depending on the temperature of the cooling water, the amount of refrigerant stored in the refrigerant storage chamber is adjusted to adjust the solution concentration. It responds to fluctuations in cooling water temperature,
When the performance of the absorber or the evaporator is deteriorated, the cooling is not effective, and there is a problem that the performance deterioration cannot be detected and the overload operation is repeated.

SUMMARY OF THE INVENTION An object of the present invention is to provide an absorption chiller / heater capable of preventing deterioration of the cooling capacity by predicting a decrease in the cooling capacity by determining the deterioration of the performance of the absorber or the evaporator and preventing overload operation by maintaining the equipment. It is to provide a control method.

[0009]

In order to achieve the above object, an absorption chiller / heater according to the present invention separates a dilute solution into a refrigerant vapor and an intermediate concentrated solution by heating a dilute solution. A separator, a high-temperature solution heat exchanger that heats the intermediate concentrated solution with a dilute solution to lower the temperature, a low-temperature regenerator that reheats the cooled intermediate concentrated solution with refrigerant vapor to generate a concentrated solution, and a dilute concentrated solution. A low-temperature solution heat exchanger that exchanges heat with the solution to lower the temperature, a condenser that condenses refrigerant vapor into liquid refrigerant with cooling water, an evaporator that evaporates liquid refrigerant to generate cold water, and absorbs the evaporated refrigerant An absorption chiller / heater comprising an absorber for cooling and producing a dilute solution by cooling water to be sent to a condenser, and a solution circulation pump for sending the dilute solution to the high-temperature regenerator through the respective heat exchangers. Evaporator temperature sensor on the evaporation side of the evaporator and cooling to cooling water A water temperature sensor provided, a configuration provided with the control means for emitting determined and alarm performance degradation of the evaporator or absorber by detecting the temperature of the evaporator temperature sensor.

The control means stores in advance an upper limit temperature and a lower limit temperature corresponding to the cooling water temperature with respect to the evaporator temperature during normal operation, and when the detected temperature of the evaporator temperature sensor is equal to or higher than the upper limit temperature, the absorber abnormality is detected. Alternatively, the controller may be configured to include a controller that determines an evaporator abnormality when the temperature is equal to or lower than the lower limit temperature and an alarm transmission device that receives an output signal of the controller and issues an alarm.

Further, in the control method of the absorption chiller / heater,
Applied to any one of the absorption chiller / heater, storing in advance the upper limit temperature and the lower limit temperature for the evaporator temperature during normal operation corresponding to the cooling water temperature, and the upper limit temperature corresponding to the detected cooling water temperature or Determining the lower limit temperature, comparing the detected evaporator temperature with the upper limit temperature or the lower limit temperature, and determining whether the absorber is abnormal when the detected evaporator temperature is higher than the upper limit temperature or abnormal when the detected evaporator temperature is lower than the lower limit temperature. The configuration includes a step of determining and a step of issuing a warning of an abnormality of the absorber or the evaporator.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, a high-temperature regenerator 1 for heating a dilute solution, a separator 2 for separating the dilute solution into a refrigerant vapor and an intermediate concentrated solution, A solution heat exchanger 7; and a low-temperature regenerator 3 for heating the cooled intermediate concentrated solution again with refrigerant vapor to generate a concentrated solution.
A low-temperature solution heat exchanger 8 for exchanging heat between a concentrated solution and a dilute solution to lower the temperature; a condenser 4 for condensing refrigerant vapor into a liquid refrigerant with cooling water; and an evaporator for evaporating the liquid refrigerant to generate cold water. 5, an absorber 6 that absorbs the evaporated refrigerant and cools it with cooling water sent to the condenser 4 to generate a dilute solution, and a high-temperature regenerator 1 that dilutes the dilute solution through the respective heat exchangers 7 and 8. An absorption chiller / heater provided with a solution circulation pump 9 for feeding the evaporator 5 to the evaporator 5 on the evaporation side of the evaporator 5.
And a cooling water temperature sensor, for example, a cooling water inlet temperature sensor 12 for the cooling water, and a control means for judging a decrease in the performance of the evaporator 5 or the absorber 6 based on the temperature detected by the evaporator temperature sensor 11 and issuing an alarm. The configuration is provided. The cooling water temperature sensor may be provided at the cooling water inlet of the condenser 4.

The control means stores in advance an upper limit temperature and a lower limit temperature corresponding to the cooling water temperature with respect to the evaporator temperature during normal operation, and when the detected temperature of the evaporator temperature sensor 11 is equal to or higher than the upper limit temperature, A controller 13 such as a microcomputer that determines that the evaporator is abnormal when the temperature is abnormal or lower than the lower limit temperature, and an alarm transmitting device 14 that receives an output signal of the controller 13 and issues an alarm.

As shown in FIG.
Is stored in advance with the evaporator temperature line A of the evaporator temperature Tn corresponding to the cooling water temperature Cn during normal operation, and the upper limit value ΔTn and the lower limit value Δtn set for the evaporator temperature line A. I have. When the cooling water temperature C ₁ and the evaporator temperature T ₁ detected by the evaporator temperature sensor 11 and the cooling water inlet temperature sensor 12 are input, evaporation on the evaporator temperature line A corresponding to the cooling water temperature C ₁ is performed. The container temperature Tn, the upper limit ΔT ₁ and the lower limit Δt ₁ are obtained. So the difference between the evaporator temperature T ₁ of the upper limit temperature or lower temperature are compared is computed, T ₁
If ≧ Tn + ΔT ₁ , it is determined that the absorber is abnormal, and T ₁ ≦ T
If n−Δt ₁ , it is determined that the evaporator is abnormal, and T ₁ ≦ Tn +
If ΔT ₁ and T ₁ ≧ Tn−Δt ₁ , both the absorber and the evaporator are determined to be normal. When it is determined that the absorber is abnormal or the evaporator is abnormal, a signal is output to the alarm transmitting device 14 to issue an alarm, and the abnormalities of the absorber or the evaporator are displayed on a display (not shown).

According to the present embodiment, an alarm is issued during the cooling operation and an abnormality of the absorber or the evaporator is displayed, so that a decrease in the cooling capacity can be predicted, and the heat transfer surface of the absorber or the evaporator can be monitored. By performing maintenance and improving the performance, overload operation can be prevented.

As another embodiment of the present invention, the control method of the absorption chiller / heater is applied to any one of the above absorption chiller / heater, and as shown in FIG. A step 21 of previously storing an upper limit value ΔTn and a lower limit value Δtn for the evaporator temperature Tn, a step 22 of calculating an upper limit value ΔT ₁ and a lower limit value Δt ₁ corresponding to the detected cooling water temperature C ₁ , The temperature T ₁ is raised to the upper limit temperature (Tn +
ΔT ₁ ) or the lower limit temperature (Tn−Δt ₁ ).
Utters 3, the step of determining 24, 26 and the evaporator abnormality in evaporator temperatures T ₁ detected is below the absorber abnormal or lower temperature during the above maximum temperature, the alarm absorber abnormal or evaporator abnormal Steps 25 and 27 are included.

According to this embodiment, the same effect as described above can be obtained.

[0018]

According to the present invention, the detected temperature of the evaporator temperature is compared with the normal temperature to indicate the abnormality of the absorber or the evaporator. By performing maintenance on the container, overload operation can be prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the embodiment shown in FIG. 1;

FIG. 3 is a flowchart showing another embodiment of the present invention.

FIG. 4 is a diagram showing a conventional technique.

[Description of Signs] 1 High temperature regenerator 2 Separator 3 Low temperature regenerator 4 Condenser 5 Evaporator 6 Absorber 7 High temperature solution heat exchanger 8 Low temperature solution heat exchanger 9 Solution circulation pump 11 Evaporator temperature sensor 12 Cooling water inlet Temperature sensor 13 Controller 14 Alarm transmitter

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 15/00 306 F25B 15/00 F25B 49/04

Claims (3)

(57) [Claims] 1. A high-temperature regenerator for heating a dilute solution, a separator for separating the dilute solution into refrigerant vapor and an intermediate concentrated solution, and a high-temperature solution for lowering the temperature by exchanging the intermediate concentrated solution with the dilute solution. A heat exchanger, a low-temperature regenerator that reheats the lowered intermediate concentrated solution with the refrigerant vapor to generate a concentrated solution, and a low-temperature solution heat exchanger that heat-exchanges the concentrated solution with the dilute solution to lower the temperature,
A condenser for condensing the refrigerant vapor into a liquid refrigerant with cooling water, an evaporator for evaporating the liquid refrigerant to generate cold water, and cooling with the cooling water for absorbing the evaporated refrigerant and sending it to the condenser. In an absorption chiller / heater comprising an absorber for producing a dilute solution and a solution circulation pump for sending the dilute solution to the high-temperature regenerator via the respective heat exchangers, the evaporator is evaporated to the evaporation side of the evaporator. A cooling water temperature sensor is provided for the cooling water temperature and the cooling water , and the cooling water temperature is set in advance according to the cooling water temperature.
Stores the lower and upper limit temperatures of the specified evaporator temperature
And, detecting the temperature of the evaporator temperature sensor, the storage of
Below the lower limit or above the upper limit
A cooling means for determining whether the performance of the evaporator or the absorber has deteriorated and issuing an alarm. 2. The absorption chiller / heater according to claim 1,
The control means stores in advance the upper limit temperature and the lower limit temperature for the evaporator temperature during normal operation corresponding to the cooling water temperature, and when the detected temperature of the evaporator temperature sensor is equal to or higher than the upper limit temperature, the absorber abnormality or the lower limit is detected. An absorption chiller / heater comprising: a controller for judging an evaporator abnormality when the temperature is lower than a temperature; and an alarm transmission device for inputting an output signal of the controller and issuing an alarm. 3. A step of storing the upper limit temperature and the lower limit temperature of the evaporator temperature during normal operation corresponding to the cooling water temperature, which is applied to the absorption chiller / heater according to claim 1; Obtaining the upper limit temperature or the lower limit temperature corresponding to the temperature, comparing the detected evaporator temperature with the upper limit temperature or the lower limit temperature, and absorbing when the detected evaporator temperature is equal to or higher than the upper limit temperature. A method for controlling an absorption chiller / heater, comprising: a step of determining an evaporator abnormality when the temperature is equal to or lower than the lower limit temperature of the evaporator; and a step of issuing a warning of the abnormality of the absorber or the evaporator abnormality.