JP7122538B2 - Absorption chiller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller, and more particularly to an absorption chiller capable of preventing an erroneous judgment of an abnormality prediction forecast when the fuel control valve of a gas burner is lowered.

Generally, an absorption chiller is known that includes a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber, which are connected by piping to form circulation paths for the absorbent and the refrigerant, respectively. Absorption chillers are used, for example, for central air conditioning in office buildings.
In such an absorption chiller, a vacuum device is used to evaporate the refrigerant. Therefore, it is necessary to promptly detect the leakage of air from the outside and the abnormal occurrence of non-condensable gas such as hydrogen gas generated inside the aircraft, and to promptly take necessary measures.

Therefore, conventionally, for example, the logarithmic mean temperature difference between the absorbing liquid and the cooling water in the absorber and the pressure of the storage chamber from which the non-condensable gas was introduced are respectively obtained, and both of these values are predetermined values A technique is disclosed in which, when a value is exceeded, an abnormality detection device outputs an abnormality signal indicating vacuum abnormality to activate an alarm device (see, for example, Patent Document 1).

JP-A-06-159851

By the way, for example, when a photochemical smog warning is issued, it may be necessary to take measures to reduce the combustion amount of the gas burner of the absorption chiller. It is common to respond by
However, in the technology for alarming a vacuum abnormality by means of an abnormality detection device, as in the above-described conventional technology, if the combustion amount of the gas burner is suddenly reduced, pressure fluctuations may occur, which may lead to an erroneous determination of a vacuum abnormality. There is a problem that there is

SUMMARY OF THE INVENTION It is an object of the present invention to provide an absorption refrigerating machine capable of preventing an erroneous judgment of an abnormality prediction forecast when the fuel control valve of a gas burner is lowered. and

In order to achieve the above object, the present invention provides a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber, which are connected by piping to form circulation paths for the absorbent and the refrigerant, respectively. The refrigerator has a control device, and the control device reduces the maximum valve opening of the fuel control valve of the gas burner when receiving an instruction to control the amount of combustion , and stops judgment of a specific abnormality prediction forecast. and the specific abnormality prediction forecast is a vacuum degree decrease forecast and a bleed performance decrease forecast .
According to this, pressure fluctuation occurs by reducing the maximum valve opening of the fuel control valve of the gas burner to a predetermined opening, but control is performed so as to stop the judgment of the abnormality prediction forecast, so that the abnormality prediction forecast is not erroneous. Judgment can be prevented.

According to the present invention, pressure fluctuation occurs by reducing the maximum valve opening of the fuel control valve of the gas burner to a predetermined opening. Misjudgment can be prevented.

1 is a schematic configuration diagram of an absorption chiller according to an embodiment; FIG. 3 is a block diagram showing a control configuration of this embodiment; FIG. 4 is a flow chart showing the operation of the embodiment;

A first invention is an absorption chiller comprising a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber, which are connected by piping to form circulation paths for an absorption liquid and a refrigerant, respectively, A control device is provided, and the control device is configured to perform combustion amount reduction control by operating an operation unit, and the combustion amount reduction control reduces the maximum valve opening degree of the fuel control valve of the gas burner to a predetermined opening degree. and control to stop the judgment of the abnormality prediction forecast.
According to this, pressure fluctuation occurs by reducing the maximum valve opening of the fuel control valve of the gas burner to a predetermined opening, but control is performed so as to stop the judgment of the abnormality prediction forecast, so that the abnormality prediction forecast is not erroneous. Judgment can be prevented.

In a second aspect of the invention, the abnormality prediction forecast is a vacuum degree decrease prediction forecast and a bleed performance decrease prediction forecast.
According to this, it is possible to prevent an erroneous judgment of the abnormality prediction forecast due to the vacuum degree decrease prediction forecast and the bleed performance decrease prediction forecast.

In a third aspect of the invention, the control device suspends determination of the abnormality prediction forecast for a predetermined time when the combustion amount reduction control is performed.
According to this, even if the maximum opening degree of the fuel control valve of the gas burner is reduced to the predetermined opening degree and the pressure fluctuation occurs, the determination of the abnormality prediction forecast is stopped for the predetermined time. After the pressure is stabilized, anomaly predictive judgment can be made.

In a fourth aspect of the invention, when the control device performs the combustion amount reduction control, the control device displays that fact on the display section.
According to this, by displaying on the display section that the combustion amount reduction control has been performed, the user can be made to recognize that fact.

In a fifth aspect of the invention, the control device cancels the combustion amount reduction control by operating the operation unit, and when the control device cancels the combustion amount reduction control, the abnormality prediction forecast is performed for a predetermined time. stop judging.
According to this, when the combustion amount reduction control is canceled, the abnormality prediction forecast can be determined after the pressure is stabilized.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an absorption chiller according to the present embodiment. The absorption chiller 100 uses water as a refrigerant and an aqueous solution of lithium bromide (LiBr) as an absorption liquid. It is an exhaust heat recovery type (so-called GENELINK) absorption chiller-heater equipped with an exhaust heat regenerator that heats with hot water at a low temperature (for example, about 80°C).

As shown in FIG. 1, the absorption refrigerator 100 includes an evaporator 1, an absorber 2 arranged in parallel with the evaporator 1, and an evaporator absorber barrel 3 housing the evaporator 1 and the absorber 2. , a high-temperature regenerator 5 equipped with a gas burner (heating means) 4, a low-temperature regenerator 6, a condenser 7 arranged in parallel with this low-temperature regenerator 6, and these low-temperature regenerator 6 and condenser 7 are housed. and a cold regenerator condenser barrel 8 .
The absorption refrigerator 100 includes a low temperature heat exchanger 12, a high temperature heat exchanger 13, a refrigerant drain heat recovery device 17, a dilute absorbent pump 45, a rich absorbent pump 47, and a refrigerant pump 48. These devices are pipe-connected via absorption liquid pipes 21, 23, 24, 25 and refrigerant pipes 31, 32, 34, 35, etc. to form a circulation path.

The evaporator 1 is provided with a cold water pipe 14 for circulating and supplying the brine heat-exchanged with the refrigerant in the evaporator 1 to a heat load (for example, an air conditioner) not shown. A partially formed heat transfer tube 14A is arranged in the evaporator 1 .
The absorber 2 and the condenser 7 are provided with cooling water pipes 15 for passing cooling water through the absorber 2 and the condenser 7 in sequence. , 15B are arranged in the absorber 2 and the condenser 7 respectively.

The absorber 2 has the function of absorbing the refrigerant vapor evaporated in the evaporator 1 into the absorbing liquid and keeping the pressure inside the evaporator absorber barrel 3 in a high vacuum state. In the lower part of the absorber 2, a dilute absorbent reservoir 2A is formed in which the dilute absorbent diluted by absorbing the refrigerant vapor is stored. One end of the liquid pipe 21 is connected. The dilute absorbent pipe 21 is provided with a branched dilute absorbent pipe 21 A that branches downstream of the dilute absorbent pump 45 .
After passing through the refrigerant drain heat recovery device 17, the branched dilute absorbent pipe 21A joins the dilute absorbent pipe 21 again on the downstream side of the low temperature heat exchanger 12 of the dilute absorbent pipe 21. The other end of the dilute absorbent pipe 21 passes through the high-temperature heat exchanger 13 and is open to the air layer portion 5B located above the heat exchange portion 5A formed in the high-temperature regenerator 5 .
The dilute absorbent pipe 21 is branched into a second branch pipe 21B on the downstream side of the low temperature heat exchanger 12 and the second branch pipe 21B opens into the low temperature regenerator 6 .

The high-temperature regenerator 5 is configured by housing a gas burner 4 in a shell 60. A heat exchange section 5A is formed above the gas burner 4 to heat and regenerate the absorbent using the flame of the gas burner 4 as a heat source. An exhaust path 40 through which exhaust gas burned by the gas burner 4 flows is connected to the heat exchange section 5A, and an exhaust gas heat exchanger 41 is provided in the exhaust path 40 . A gas pipe 61 supplied with fuel gas and an intake pipe 63 supplied with air from a blower 62 are connected to the gas burner 4. Fuel gas and air are connected to these gas pipe 61 and intake pipe 63. A fuel control valve 64 is provided to control the amount of

Formed on the side of the heat exchanging portion 5A is an intermediate absorbent reservoir 5C in which the intermediate absorbent flowing out of the heat exchanging portion 5A after being thermally regenerated in the heat exchanging portion 5A is accumulated. One end of a second intermediate absorbent pipe 23 is connected to the lower end of the intermediate absorbent reservoir 5C, and the second intermediate absorbent pipe 23 is provided with a high-temperature heat exchanger 13 . The high-temperature heat exchanger 13 heats the absorbent flowing through the first intermediate absorbent tube 22 with the heat of the high-temperature intermediate absorbent flowing out of the intermediate absorbent reservoir 5C. We are trying to reduce fuel consumption.
The other end of the second intermediate absorbent pipe 23 is connected to a rich absorbent pipe 25 that connects the low temperature regenerator 6 and the absorber 2 . The upstream side of the high-temperature heat exchanger 13 of the second intermediate absorbent pipe 23 and the absorber 2 are connected by an absorbent pipe 24 with an on-off valve V1 interposed therebetween.

The low-temperature regenerator 6 uses the refrigerant vapor separated by the high-temperature regenerator 5 as a heat source to heat and regenerate the absorbent accumulated in the absorbent reservoir 6A formed in the low-temperature regenerator 6. , a heat transfer pipe 31A formed in a part of the refrigerant pipe 31 extending from the upper end of the high temperature regenerator 5 to the bottom of the low temperature regenerator 6 is arranged. By circulating the refrigerant vapor through the refrigerant pipe 31, the heat of the refrigerant vapor is transmitted to the absorbent accumulated in the absorbent reservoir 6A via the heat transfer pipe 31A, and the absorbent is further concentrated.
One end of a thick absorbent pipe 25 is connected to the absorbent reservoir 6A of the low-temperature regenerator 6, and the other end of the thick absorbent pipe 25 is connected to a thick liquid sprayer provided above the air layer portion 2B of the absorber 2. 2C is connected. A concentrated absorbent pump 47 and a low-temperature heat exchanger 12 are provided in the concentrated absorbent pipe 25 . The low-temperature heat exchanger 12 heats the dilute absorbent flowing through the dilute absorbent tube 21 with the heat of the concentrated absorbent flowing out of the absorbent reservoir 6B of the low-temperature regenerator 6 .

A bypass pipe 27 that bypasses the concentrated absorbent pump 47 and the low-temperature heat exchanger 12 is provided in the concentrated absorbent pipe 25 .
When the operation of the concentrated absorbent pump 47 is stopped, the absorbent accumulated in the absorbent reservoir 6A of the low temperature regenerator 6 is supplied into the absorber 2 through the concentrated absorbent pipe 25 and the bypass pipe 27 .

As described above, the gas layer portion 5B of the high-temperature regenerator 5 and the refrigerant liquid reservoir 7A formed at the bottom of the condenser 7 are connected by the refrigerant pipe 31 . The refrigerant pipe 31 includes a heat transfer pipe 31A connected to the absorbent reservoir 6A of the low-temperature regenerator 6 and a refrigerant drain heat recovery device 17. It is connected to the portion 2B by a refrigerant pipe 32 in which an on-off valve V2 is interposed.
One end of a refrigerant pipe 34 through which the refrigerant flowing out from the refrigerant reservoir 7A flows is connected to the refrigerant reservoir 7A of the condenser 7, and the other end of the refrigerant pipe 34 is a downwardly curved U-seal portion 34A. is connected to the gas layer portion 1A of the evaporator 1 via the .
Below the evaporator 1, a refrigerant reservoir 1B in which liquefied refrigerant is accumulated is formed. It is connected by a refrigerant pipe 35 in between.

The cooling water pipe 15 is provided with a cooling water inlet temperature sensor 36 for detecting the temperature of the cooling water flowing through the cooling water pipe 15 on the inlet side and a cooling water outlet temperature sensor 37 for detecting the temperature on the cooling water outlet side. there is A dilute absorbent outlet temperature sensor 38 for detecting the temperature of the absorbent is provided in the dilute absorbent pipe 21 on the outlet side of the absorber 2 , and the refrigerant temperature of the refrigerant pipe 34 on the outlet side of the condenser 7 is measured. A condensed refrigerant temperature sensor 39 is provided to detect .

The absorption chiller 100 of the present embodiment also includes an air bleeder 70 , and the air bleeder 70 includes a storage tank 71 . An air extraction pipe 72 communicating with the air layer portion 2B of the absorber 2 is connected to the upper portion of the storage tank 71 . A return pipe 73 communicating with the bottom of the absorber 2 is connected to the bottom of the storage tank 71 . Furthermore, an absorbent pipe 75 connected to the dilute absorbent pipe 21 via an ejector pump 74 is connected to the upper portion of the storage tank 71 .
The storage tank 71 is provided with a tank pressure sensor 76 for detecting the internal pressure of the storage tank 71 .

By driving the ejector pump 74 , the dilute absorbent in the dilute absorbent tube 21 is taken into the reservoir tank 71 through the absorbent tube 75 . Due to the dilute absorbent flowing through the absorbent pipe 75, the inside of the storage tank 71 becomes negative pressure. is guided above the reservoir tank 71 through the air bleed pipe 72 .

Of the gas led to the storage tank 71, the refrigerant vapor and the vaporized absorbent dissolve and are absorbed by the absorbent accumulated below the storage tank 71, but the non-condensable gas dissolves in the absorbent. Since the water cannot be discharged, it is stored above the storage tank 71 . Then, the absorbent accumulated below the storage tank 71 is returned to the absorber 2 through the return pipe 73 .

Next, the control configuration of this embodiment will be described.
FIG. 2 is a block diagram showing the control configuration of this embodiment.
As shown in FIG. 2 , the absorption chiller 100 of this embodiment includes a controller 50 , and the controller 50 includes a control device 51 . The control device 51 centrally controls each part of the absorption chiller 100, and includes a CPU as an arithmetic execution part, a ROM that non-volatilely stores a basic control program that can be executed by the CPU, predetermined data, and the like. , a memory 52 such as a RAM, and other peripheral circuits.

Further, detection signals from the cooling water inlet temperature sensor 36, the cooling water outlet temperature sensor 37, the dilute absorbent outlet temperature sensor 38, the condensed refrigerant temperature sensor 39, and the tank pressure sensor 76 are input to the controller 51, respectively. It is configured.
The controller 50 also includes a timer 53, an operation section 54, a notification section 55, and a display section 56, respectively.

The control device 51 of the controller 50 controls the fuel control valve 64 of the gas burner 4 of the absorption chiller 100 to control combustion by the gas burner 4, and to control the lean absorbent pump 45, the intermediate absorbent pump 46, and the rich absorbent pump 46. It is configured to drive and control the liquid pump 47 and the refrigerant pump 48 . Furthermore, the control device 51 of the controller 50 performs inverter control of the dilute absorbent pump 45, the intermediate absorbent pump 46, the rich absorbent pump 47, and the refrigerant pump 48, so that the dilute absorbent pump 45, the intermediate absorbent pump 46 , the concentrated absorbent pump 47 and the refrigerant pump 48 are configured to control the flow rate. Also, the control device 51 is configured to control the opening and closing of the valves V1 and V2.

In the present embodiment, the control device 51 controls the abnormality prediction forecast. The abnormality prediction forecast is, for example, a vacuum degree decrease forecast and a bleed performance decrease forecast.
Next, the vacuum degree decrease prediction forecast will be described.
The controller 51 detects the internal pressure P of the reservoir tank 71 with the tank pressure sensor 76, and controls the extraction device 70 so that the internal pressure is maintained at, for example, 7 kPa/h to 10 kPa/h. It is Specifically, when the internal pressure of the storage tank 71 reaches 10 kPa/h, the extraction device 70 is operated to reduce the internal pressure of the storage tank 71, and when the internal pressure of the storage tank 71 reaches 7 kPa/h, is for controlling the bleeding device 70 to be stopped.

In addition, the control device 51 obtains changes in the internal pressure of the storage tank 71 . Specifically, the control device 51 detects the internal pressure of the storage tank 71 at regular intervals (for example, every 30 minutes), acquires the previously detected internal pressure P1 and the current internal pressure P2, By obtaining the difference between the internal pressure P1 and the internal pressure P2, the change in the internal pressure per hour is obtained.
The control device 51 determines whether the change in internal pressure is within a predetermined range, as shown by the following formula.
1.0 (kPa/h) ≤ internal pressure change (kPa/h) ≤ 1.6 (kPa/h)
The range of 1.0 kPa/h to 1.6 kPa/h can be set arbitrarily, and is not limited to the values shown here.

The control device 51 also obtains the gradient {Δ(Δp/Δt)} (kPa/h) of the internal pressure change of the storage tank 71 .
According to the studies of the applicants, the slope of the internal pressure change of the storage tank 71 is different when the inhibitor concentration is lowered and when the vacuum leak occurs. It was found that the slope is small and the slope becomes large when a vacuum leak occurs.
Therefore, as described above, when the internal pressure change of the storage tank 71 is in the range of 1.0 kPa/h to 1.6 kPa/h, the control device 51 controls the internal pressure change is a predetermined value of 0.3 kPa/h or less.
Gradient of change in storage chamber pressure {Δ(Δp/Δt)} (kPa/h) ≤ 0.3 (kPa/h)
The predetermined value of 0.3 kPa/h can be set arbitrarily, and is not limited to the numerical value shown here.

When the control device 51 determines that the slope of the internal pressure change is 0.3 kPa/h or less, the notification unit 55 issues a forecast that the concentration of the inhibitor inside the storage tank 71 has decreased. to control.
Further, when the control device 51 determines that the slope of the internal pressure change is greater than 0.3 kPa/h, the notification unit 55 issues a forecast that the inhibitor concentration inside the storage tank 71 has decreased. Control to release. This is because when the slope of the internal pressure change is greater than 0.3 kPa/h, it is considered that the concentration of the inhibitor is not decreasing, but rather that vacuum leakage has occurred. The reporting unit 55 may report that a vacuum leak has occurred.

Next, the bleed performance deterioration prediction forecast will be described.
In the present embodiment, the control device 51 obtains the dilute absorbent outlet temperature T1 and the cooling water inlet temperature T2 detected by the dilute absorbent outlet temperature sensor 38 and the cooling water inlet temperature sensor 36, It is determined whether temperature T1-cooling water inlet temperature T2.gtoreq.predetermined temperature difference T3. Then, the control device 51 determines whether or not the dilute absorbent outlet temperature T1−cooling water inlet temperature T2 is equal to or greater than a predetermined temperature difference T3 for a predetermined time (for example, 30 minutes). conditions).
In general, the temperature difference between the dilute absorbent outlet temperature T1 and the cooling water inlet temperature T2 is designed to be about 5°C, which is +2°C with respect to the design temperature difference, that is, the predetermined temperature difference T3. It is determined whether or not the temperature has reached 7°C or higher.

The control device 51 acquires the refrigerant condensing temperature T4 and the cooling water outlet temperature T5 detected by the cooling water outlet temperature sensor 37 and the condensed refrigerant temperature sensor 39, and determines that the refrigerant condensing temperature T4−cooling water outlet temperature T5≧predetermined temperature difference. It is determined whether or not T6 has been reached. Then, the control device 51 determines whether or not the state in which the refrigerant condensing temperature T4-cooling water outlet temperature T5 is equal to or greater than a predetermined temperature difference T6 has continued for a predetermined time (for example, 30 minutes) (second condition). .
In general, when the temperature difference between the refrigerant condensing temperature T4 and the cooling water outlet temperature T5 is greater than a certain value, it is considered that non-condensable gas remains inside the condenser and the heat exchange efficiency is reduced. and, for example, the predetermined temperature difference T6 is set to 5°C.

Then, when the control device 51 determines that the above-described first condition is satisfied, or determines that both the first condition and the second condition are satisfied, the notification unit 55 indicates that the air bleed performance is insufficient. It is configured to issue a forecast to the effect that there is.

Generally, when, for example, a photochemical smog warning is issued during cooling operation, it is required to take measures to reduce the combustion amount of the gas burner 4 .
In this case, in the present embodiment, the control device 51 is configured to perform combustion amount reduction control by operating the operation unit 54 .
The combustion amount reduction control is performed by reducing the maximum opening degree of the fuel control valve 64 of the gas burner 4 to a predetermined opening degree. Specifically, the maximum valve opening is changed from 100% to 50%.
In addition, the control device 51 performs control so as not to judge abnormality prediction forecast when the maximum valve opening degree is reduced by the combustion amount reduction control. Specifically, the abnormality prediction forecast is the above-mentioned vacuum degree decrease prediction forecast and extraction performance deterioration prediction forecast, and the control device 51 stops the judgment regarding these vacuum degree decrease prediction forecast and extraction performance decrease prediction forecast. control.

That is, the vacuum degree decrease prediction forecast judges the degree of vacuum based on the recovery rate of the non-condensable gas, and the extraction performance deterioration prediction forecast determines the extraction performance based on the operating temperature. If the valve opening degree is lowered to rapidly lower the combustion amount, the non-condensable gas will temporarily increase due to the influence of the pressure fluctuation. Therefore, the possibility of misjudgment may increase.

Further, the stop control for determining the abnormality prediction forecast in the combustion amount reduction control is performed for a predetermined period of time. Specifically, it is performed until 30 to 60 minutes have passed since the maximum valve opening degree of the fuel control valve 64 of the gas burner 4 was lowered. This is because it is thought that the pressure will stabilize and the amount of non-condensable gas will also stabilize 30 to 60 minutes after the maximum valve opening degree of the fuel control valve 64 of the gas burner 4 is lowered. The time for stopping judgment of the abnormality prediction forecast is not limited to 30 minutes to 60 minutes, and may be set to any time as long as the operating state is stabilized.
Note that, when the combustion amount reduction control is performed, the control device 51 may cause the display unit 56 to display that the combustion amount reduction control is being performed. By displaying on the display unit 56 that the combustion amount reduction control is being performed in this way, the user can be made aware of this.

Then, when the operation unit 54 is operated to cancel the combustion amount reduction control, the control device 51 cancels the combustion amount reduction control. Then, the control device 51 performs control so as not to judge the abnormality prediction forecast until a predetermined period of time has elapsed after the cancellation. The predetermined time is the time required for the operating state to stabilize, and is, for example, 30 to 60 minutes.

It should be noted that the present embodiment is applied when combustion amount reduction control is performed during cooling operation. During heating operation, if the combustion amount reduction control is performed, the amount of non-condensable gas collected will not temporarily increase due to the effects of pressure fluctuations, so it is necessary to perform control to stop the abnormality prediction forecast judgment. no.

Next, the operation of this embodiment will be described.
During a cooling operation such as cooling, brine (for example, cold water) is circulated and supplied to a heat load (not shown) through the cold water pipe 14 . The control device 51 controls the amount of heat input to the absorption chiller 100 so that the outlet temperature of the brine evaporator 1 becomes a predetermined set temperature, for example, 7°C.
Specifically, the control device 51 activates all the pumps 45, 47, and 48 and controls the combustion of the gas in the gas burner 4 so that the temperature of the brine measured by the cold water outlet temperature sensor 36 reaches a predetermined level. The heating power of the gas burner 4 is controlled so that the temperature becomes 7°C.

In this case, the lean absorbent from the absorber 2 is heated by the lean absorbent pump 45 via the lean absorbent tube 21 via the low temperature heat exchanger 12 and the high temperature heat exchanger 13 or the exhaust gas heat exchanger 41. It is sent to the high temperature regenerator 5 .
The absorbent sent to the high-temperature regenerator 5 is heated by the flame from the gas burner 4 and the high-temperature combustion gas in the high-temperature regenerator 5, so that the refrigerant in the absorbent evaporates and separates. The intermediate absorbent whose concentration has increased by evaporating and separating the refrigerant in the high-temperature regenerator 5 is sent to the concentrated absorbent pipe 25 via the high-temperature heat exchanger 13 and joins the absorbent that has passed through the low-temperature regenerator 6. .

On the other hand, the absorbent sent to the low-temperature regenerator 6 is heated by the high-temperature refrigerant vapor that is supplied from the high-temperature regenerator 5 through the refrigerant pipe 31 and flows into the heat transfer pipe 31A. This concentrated absorbent is combined with the absorbent that has passed through the high-temperature regenerator 5, and is sent to the absorber 2 via the low-temperature heat exchanger 12 by the concentrated absorbent pump 47, whereupon it is sent to the concentrated liquid sprayer 2C. is distributed from

The refrigerant separated and produced by the low-temperature regenerator 6 enters the condenser 7, is condensed, and accumulates in the refrigerant liquid reservoir 7A. When a large amount of refrigerant liquid accumulates in the refrigerant liquid reservoir 7A, this refrigerant liquid flows out from the refrigerant liquid reservoir 7A, enters the evaporator 1 via the refrigerant pipe 34, is pumped by the operation of the refrigerant pump 48, and is dispersed. It is sprayed from the vessel 1C onto the heat transfer tubes 14A of the cold water tubes 14.
Since the refrigerant liquid sprayed over the heat transfer tubes 14A takes the heat of vaporization from the brine passing through the heat transfer tubes 14A and evaporates, the brine passing through the heat transfer tubes 14A is cooled, and the brine whose temperature has been lowered in this way is cooled. Cooling operation such as cooling is performed by supplying the heat load from the cold water pipe 14 .
The refrigerant evaporated in the evaporator 1 enters the absorber 2 and is absorbed by the concentrated absorbent supplied from the low-temperature regenerator 6 and sprayed from above. The circulation of the absorbent pump 45 to the high-temperature regenerator 5 is repeated.

Next, control according to this embodiment will be described with reference to the flowchart shown in FIG.
In the present embodiment, when the operation unit 54 is operated to perform combustion amount reduction control while the cooling operation is being performed (ST1), the control device 51 performs the combustion amount reduction control. (ST2). That is, the control device 51 reduces the maximum opening degree of the fuel control valve 64 of the gas burner 4 to a predetermined opening degree.
Then, the control device 51 determines whether or not a predetermined time has elapsed since the start of the combustion amount reduction control (ST3), and until the predetermined time has elapsed (ST3: NO), the abnormality prediction forecast is not determined. (ST4).
If it is determined that the predetermined time has passed (ST3: YES), the control device 51 starts determination of an abnormality prediction forecast. After that, operation control is performed with the decreased valve opening degree of the fuel control valve 64 of the gas burner 4 as the maximum valve opening degree.

When the control device 51 is operated to cancel the combustion amount reduction control, the control device 51 cancels the combustion amount reduction control (ST5).
Then, the control device 51 determines whether or not a predetermined period of time has elapsed since the cancellation of the combustion amount reduction control (ST6), and until the predetermined period of time has elapsed (ST6: NO), the abnormality prediction forecast is not determined. (ST7).
If it is determined that the predetermined time has passed (ST6: YES), the control device 51 starts determination of an abnormality prediction forecast. After that, operation control is performed with the maximum valve opening (100%) of the fuel control valve 64 of the gas burner 4 .

In the present embodiment, when the combustion amount reduction control is canceled by the control device 51, the abnormality prediction forecast is not judged until a predetermined period of time elapses. may be controlled so that an abnormality prediction forecast is determined immediately when is released.
As a result, when the fuel control valve 64 of the gas burner 4 is controlled at the maximum valve opening, it is possible to immediately issue an abnormality prediction such as a vacuum degree decrease prediction prediction and a bleed performance deterioration prediction prediction.

As described above, in the present embodiment, the control device 51 is configured to perform combustion amount reduction control by operating the operation unit 54. The combustion amount reduction control is performed by operating the fuel control valve 64 of the gas burner 4. Control is performed so that the maximum valve opening degree is lowered to a predetermined opening degree, and the determination of the abnormality prediction forecast is stopped.
According to this, pressure fluctuation occurs by reducing the maximum valve opening degree of the fuel control valve 64 of the gas burner 4 to a predetermined degree of opening, but since control is performed so as to stop the determination of the abnormality prediction forecast, the abnormality prediction forecast is performed. erroneous judgment can be prevented.

Further, in the present embodiment, the abnormality prediction forecast is the vacuum degree decrease prediction forecast and the extraction performance decrease prediction forecast.
According to this, it is possible to prevent an erroneous judgment of the abnormality prediction forecast due to the vacuum degree decrease prediction forecast and the bleed performance decrease prediction forecast.

Further, in the present embodiment, when the combustion amount reduction control is performed, the control device 51 suspends the determination of the abnormality prediction forecast for a predetermined time.
According to this, even if the maximum valve opening degree of the fuel control valve 64 of the gas burner 4 is reduced to the predetermined opening degree and pressure fluctuation occurs, the determination of the abnormality prediction forecast is stopped for the predetermined time, so the predetermined time elapses. After the pressure is stabilized, the abnormality prediction forecast can be judged.

Further, in the present embodiment, when the control device 51 performs the combustion amount reduction control, the control device 51 causes the display section 56 to display that fact.
According to this, by displaying on the display unit 56 that the combustion amount reduction control has been performed, the user can be made to recognize that effect.

Further, in the present embodiment, the control device 51 cancels the combustion amount reduction control by operating the operation unit 54, and when the combustion amount reduction control is canceled, the control device 51 performs the abnormality prediction forecast for a predetermined time. Stop judging.
According to this, when the combustion amount reduction control is canceled, the abnormality prediction forecast can be determined after the pressure is stabilized.

In addition, this embodiment shows one aspect|mode to which this invention is applied, Comprising: This invention is not limited to the said embodiment.
For example, in the present embodiment, a configuration including a gas burner 4 that performs heating by burning fuel gas as a heating means for heating the absorbent in the high-temperature regenerator has been described, but the present invention is not limited to this. , a configuration including a gas burner for burning kerosene or heavy oil A, or a configuration in which heat such as steam or exhaust gas is used for heating.

1 evaporator 2 absorber 4 gas burner 5 high temperature regenerator 6 low temperature regenerator 7 condenser 12 low temperature heat exchanger 13 high temperature heat exchanger 36 cooling water inlet temperature sensor 37 cooling water outlet temperature sensor 38 dilute absorbent outlet temperature sensor 39 condensation Refrigerant temperature sensor 45 Dilute absorbent pump 46 Intermediate absorbent pump 47 Rich absorbent pump 48 Refrigerant pump 50 Controller 51 Control device 52 Memory 53 Timer 54 Operation unit 55 Notification unit 56 Display unit 64 Fuel control valve 70 Bleed device 76 Tank pressure sensor 100 absorption refrigerator

Claims (8)

An absorption chiller comprising a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber, which are connected by piping to form circulation paths for the absorbing liquid and the refrigerant, respectively,
with a control device,
The control device reduces the maximum valve opening of the fuel control valve of the gas burner when receiving an instruction to reduce the amount of combustion , and controls to stop judgment of a specific abnormality prediction forecast ,
The absorption refrigerating machine , wherein the specific abnormality prediction forecast is a vacuum degree decrease forecast and a bleed performance decrease forecast . An absorption chiller comprising a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber, which are connected by piping to form circulation paths for the absorbing liquid and the refrigerant, respectively,
with a control device,
The control device reduces the maximum valve opening degree of the fuel control valve of the gas burner when receiving an instruction for combustion amount reduction control, and stops judgment of a specific abnormality prediction forecast,
The absorption chiller according to claim 1, wherein the specific anomaly prediction forecast is an anomaly prediction forecast caused by pressure fluctuations caused by reducing the maximum valve opening of a fuel control valve of the gas burner. 3. The absorption chiller according to claim 1 , wherein the determination of the specific abnormality prediction forecast is stopped for a predetermined period of time . 4. The absorption chiller according to any one of claims 1 to 3, wherein the control device causes a display unit to display that the combustion amount reduction control is being executed . 5. The control device according to any one of claims 1 to 4, characterized in that , even when the combustion amount reduction control is canceled, the control device suspends determination of the specific abnormality prediction forecast for a predetermined time. absorption chiller. 6. The control device according to any one of claims 1 to 5, wherein the control device reduces the maximum valve opening degree of the fuel control valve of the gas burner to a predetermined opening degree when receiving the instruction for the combustion amount reduction control. or the absorption chiller according to claim 1. 7. The absorption chiller according to claim 6, wherein said predetermined opening is 50%. 8. The absorption chiller according to any one of claims 1 to 7, wherein the control for stopping determination of the specific abnormality prediction forecast is applied during cooling operation and not applied during heating operation.

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