JP3313880B2 - Air conditioner using absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner using an absorption refrigerator for general houses and small buildings, and more particularly, adjusts cooling capacity by comparing the outside air temperature with a past temperature change. The present invention relates to an air conditioner capable of improving cooling efficiency.

[0002]

2. Description of the Related Art Air conditioners using absorption chillers are currently mainly used for industrial and commercial facilities such as buildings and large stores.

In a cooling system of an air conditioner using an absorption refrigerator, a refrigerant vapor evaporated in a regenerator is condensed in a water-cooled condenser, and the condensed refrigerant is guided to an evaporator to evaporate. The cooling medium (usually water) circulating between the fan coil unit provided in the room to be cooled by the latent heat of evaporation and the refrigerator is cooled. On the other hand, the operation is performed in a cycle in which the evaporated refrigerant vapor is absorbed into a concentrated solution (absorbing liquid) by a water-cooled absorber and returned to the regenerator again.

In an air conditioner using an absorption type refrigerator of this type, the temperature of a cooling medium circulated in an indoor fan coil unit is cooled to about 7 ° C. in an evaporator, and the cooling medium is cooled in a fan coil in the room. To cool the room air and return it to the evaporator at around 12 ° C. When an aqueous solution of lithium bromide is used as the absorbing solution, it is necessary to maintain the temperature of the absorbing solution in the absorber at around 40 ° C. In order to maintain this temperature, a cooling tower is installed on a rooftop or the like to provide a water cooling circuit. The method of cooling with is taken.

[0005] However, the conventional air-conditioning apparatus using a water-cooled absorption chiller has the following problems.

(1) Since the temperature of the absorber is controlled by a water-cooling method, the equipment becomes large and piping is required, which requires a lot of construction cost, and is necessary for general houses and small-scale buildings. Not suitable for cooling.

(2) Since it is necessary to connect the fan coil unit in the room to be cooled and the refrigerator with a pipe for circulating cooling medium, construction costs and equipment costs are high. This is the same for an ammonia absorption refrigerator using ammonia water as the absorbing liquid and the refrigerant.

Therefore, during cooling operation, the present inventors cooled the condenser and the absorber using an air-cooling system instead of a water-cooling system, and sent the refrigerant from the condenser to the evaporator without using a pump. A patent application has already been filed for an air conditioner that has a cooling mode in which the evaporator is located in a passage through which room air to be air-conditioned passes, and the indoor air is cooled by directly touching the outside of the evaporator, while performing pressure difference. (Japanese Patent Application No. 5-2351 / 1993).

FIG. 6 shows a main part of a modification of an air conditioner using a single-effect absorption refrigerator proposed in the above-mentioned application, and FIG.
Indicates the installation state of the air conditioner.

[0010] As shown in FIG.
The outdoor unit 1 has a configuration as shown in FIG. 6 and is disposed outside the room 5 of the house to be air-conditioned. The indoor unit 2 has only a cool air outlet and a room air inlet. And is disposed inside the chamber 5. The outdoor unit 1 and the indoor unit 2 are connected by a cooling air blow duct 3 and a room air intake duct 4. A blower fan 11 is provided at a predetermined position in the blower duct 3 or the intake duct 4. Reference numeral 6 denotes a remote controller for starting or stopping the operation of the air conditioner, setting or canceling automatic operation, setting the room temperature, setting the amount of cool air to be blown, and the like.

The interior of the outdoor unit 1 is configured as shown in FIG. 6, in which an aqueous solution of lithium bromide is used as an absorbing liquid and water is used as a refrigerant.

The evaporator 10 is installed at a position where the blow duct 3 and the intake duct 4 are connected to each other. The evaporator 10 evaporates the refrigerant by a depressurizing action inside the evaporator 10 and cools it from the inside by the action of latent heat of vaporization (heat of vaporization). receive.

The regenerator 12 has a function of heating the absorbing liquid (dilute solution) having a reduced concentration by absorbing the refrigerant with the burner 13 to generate refrigerant vapor and concentrating the concentration of the absorbing liquid. Fuel supply pipe 1 to burner 13
Fuel gas is supplied from the fuel gas supply 4, and the degree of combustion is appropriately adjusted by the fuel supply control valve 15 in accordance with the input cooling capacity or the like.

The condenser 16 has a function of cooling and liquefying the refrigerant vapor sent from the regenerator 12 by the air cooling fan 17 and sending out the liquefied refrigerant to the evaporator 10.

Reference numeral 18 denotes a refrigerant tank for adjusting the total amount of the refrigerant circulating in the air conditioner and for storing a part of the refrigerant in order to adjust the concentration of the dilute solution supplied to the regenerator 12. And is connected to the condenser 16 via a valve V5.

The absorber 20 stores the absorbing liquid, and
And has a function of absorbing the refrigerant evaporated in the above into the absorbing liquid. The absorbent whose concentration has been lowered by absorbing the refrigerant is temporarily stored in the dilute solution tank 21. The absorber 20 is air-cooled by the same air-cooling fan 17 as the condenser 16.

Reference numeral 22 denotes heat for exchanging heat between the low-concentration low-temperature absorbent flowing from the dilute solution tank 21 to the regenerator 12 and the high-concentration high-temperature absorbent flowing from the regenerator 12 to the absorber 20. An exchanger 23 is a pump that absorbs the refrigerant and sends out the absorbent having a reduced concentration from the dilute solution tank 21 to the regenerator 12. A pump 24 is provided between the upstream side of the evaporator 10 and the downstream side of the condenser 16. It is a capillary or a pressure loss means corresponding to the capillary provided between them.

Each of V1, V2, V3, V4, and V5 is a regulating valve such as a solenoid valve. In particular, V4 is a regulating valve having a check valve function.

The above air conditioner basically controls each vessel by controlling the temperature of each vessel except that a pump 23 is used to send the absorbing solution from the dilute solution tank 21 to the regenerator 12. A pressure difference is created between them, and the refrigerant and the absorbing liquid are sent out and circulated by the pressure difference.

[0020]

However, in an air conditioner using such an absorption refrigerator, when the amount of refrigerant stored in the refrigerant tank is increased, the average concentration of the absorption liquid is increased and the operation efficiency is improved. it can. However, in order to increase the concentration of the absorber liquid, the generated refrigerant is sent to the refrigerant tank 18, so that the amount of refrigerant supplied to the evaporator 10 is reduced, and the cooling capacity is reduced during that time.

Furthermore, the concentrated absorbing solution, that is, the aqueous solution of lithium bromide, has a high crystallization temperature and may be crystallized. Therefore, when the outside air temperature decreases or when the operation is stopped, the concentration in the refrigerant tank is reduced. It is necessary to reduce the concentration of the solution by injecting the refrigerant. Therefore, when the outside air temperature is lowered immediately after concentration or when the operation is stopped, the concentrated solution is diluted in a short time,
The concentration operation may be wasted.

The present invention has been made in view of the above points, and has a regenerator for heating an absorbing solution (dilute solution) that has absorbed a refrigerant to generate a refrigerant vapor and a concentrated solution, and a regenerator for the regenerator. A heater for heating, a condenser for condensing refrigerant vapor generated in the regenerator, a refrigerant tank for storing condensed refrigerant, an evaporator for vaporizing the refrigerant sent from the condenser, and absorbing the refrigerant An absorber for storing the absorbing liquid to be absorbed and absorbing the refrigerant vapor vaporized in the evaporator to the absorbing liquid, an air cooling fan for cooling the absorber and the condenser together, and the evaporator provided therein, A duct having an inlet and an outlet, and introducing cooling target room air provided in the duct, and after directly cooling the room air by the evaporator,
A blower fan for blowing the cooled air into the room from the outlet, and measuring means for measuring the outside air temperature; controlling the heater in response to a change in the outside air temperature; It is an object of the present invention to improve the cooling efficiency by preventing the useless concentration of a dilute solution in an air conditioner using an absorption refrigerator in which the concentration of water is varied.

[0023]

According to the present invention, there is provided a regenerator for heating a dilute solution having a refrigerant absorbed in an absorbing liquid to generate a refrigerant vapor and a concentrated absorbing liquid. A heater for heating the regenerator, a condenser for condensing refrigerant vapor generated in the regenerator, a refrigerant tank for storing the condensed refrigerant, and an evaporator for vaporizing the refrigerant sent from the condenser. An absorber that stores the absorbing liquid and absorbs the refrigerant vapor vaporized in the evaporator into the absorbing liquid, an air-cooling fan that cools both the absorber and the condenser, and the evaporator, A duct having a suction port and an air outlet in the room, introducing cooling target indoor air provided in the duct, and directly cooling the indoor air by the evaporator, and then cooling the cooled air from the air outlet. A fan that blows air into the room, An air conditioner using an absorption refrigerator that includes a measurement unit that measures the temperature, controls the amount of refrigerant stored in the refrigerant tank in accordance with a change in outside air temperature, and adjusts the concentration of the absorption liquid. A first storage means for storing a change in the past outside air temperature, and comparing the change in the past outside air temperature with the current outside air temperature when the current outside air temperature reaches a temperature at which the concentration of the absorbent is concentrated, Calculating means for calculating a time width T in which the concentration of the absorbent needs to be concentrated; second memory means for storing a reference time T0; and concentration of the absorbent when it is determined that the time width T is longer than the reference time T0. An air conditioner using an absorption refrigerator was provided with control means for performing the operation.

[0024]

The measuring means measures the change of the outside air temperature in the past several days, and the first storage means stores the result. When the current outside air temperature measured by the measurement unit rises to a temperature that requires concentration of the absorbing solution, the calculation unit compares the current outside air temperature with the past outside air temperature change, and performs the same as the past temperature change. Assuming that the current temperature fluctuates in a simple pattern, a time t2 at which the temperature will reach a temperature at which the dilute solution is diluted in that case is estimated, and a time width T from the current time t1 to the estimated time t2 is calculated. Calculate.

Next, the control means compares the calculated time width T with the reference time T0 stored in the second storage means, and determines that the time width T is longer than the reference time T0. The absorption liquid is concentrated.

Therefore, when the outside air temperature drops to the dilution temperature in a short time even after performing the enrichment operation, the operation for increasing the concentration is not performed, and the loss of fuel due to the enrichment operation and the temporary cooling. Efficient operation can be performed without causing a decrease in capacity. When it is determined that the time width required for concentration is sufficiently long, concentration is performed. In this case, high-efficiency operation can be performed for a long time, and as a result, good efficiency can be obtained. it can.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an air conditioner according to the present invention will be described with reference to the drawings.

FIG. 2 shows an embodiment of an air conditioner using a single-effect absorption refrigerator according to the present invention.

Since the outline of the mechanical structure of the air conditioner according to the present invention is substantially the same as that shown in FIG. 6, the description of the same parts will be omitted, and the different parts and the electric circuits necessary for controlling the air conditioner will be described. .

In FIG. 2, T1 is a sensor for detecting a room temperature provided on the upstream side of the evaporator 10, T2 is a sensor for detecting the blast temperature, T3 is a sensor for detecting the liquid level of the regenerator 12, and T4. Is a sensor for detecting the temperature of the condenser 16, T
5 is a sensor as a measuring means for measuring the outside air temperature, T6
Is a sensor for detecting the liquid level of the refrigerant tank 18.

Further, a setting signal from the controller 30 including a CPU, a memory, and a driving circuit, and a setting signal from the remote controller 6 (see FIG. 7) are received by the receiving section 2a of the indoor unit 2, and the receiving section 2a
The controller 30 receives a signal from the sensors T1, T2 and the like and a signal from the communication controller 31, and receives signals from the communication controller 31.
1. The operation of the air-cooling fan 17, the burner 13, the pump 23 and the like is controlled.

For example, when the set temperature is changed,
The amount of refrigerant generated is changed by adjusting the amount of combustion of the heater 13 accordingly, and when the outside air temperature changes, the concentration of the absorbing liquid is changed corresponding to the outside air temperature. The concentration of the absorption liquid is performed by increasing the amount of combustion of the heater 13 to increase the amount of generated refrigerant, and storing the generated refrigerant in the refrigerant tank 18.

Further, the controller 30 comprises a first storage means 7, a second storage means 8, a calculation means 39, and a control means 40 as shown in FIG. The first storage means 7 stores the sensor T
The storage means is connected to an arithmetic means 39 and a control means 40. The storage means stores the change of the outside air temperature in the past several days measured by the sensor T5 together with the time. The second storage unit 8 is a storage unit that stores the reference time T0, and is connected to the control unit 40. When the concentration of the solution is concentrated, the reference time T0 is obtained by comparing the energy required for the concentration with the high efficiency obtained by the concentration, and operating at a high efficiency obtained by concentrating the energy required for the concentration. The minimum uptime at which the profit gained is greater. The reference time T0 may be changed in accordance with the degree to which the density is changed.

The calculating means 39 determines the time difference T based on the past temperature change data from the first storage means 7. A method for obtaining the time difference T will be described with reference to FIG. FIG. 4 is a graph showing the temperature on the vertical axis and the time on the horizontal axis, in which the average data of the outside air temperature in the past several days and the measurement result of the day are described until time t1.

Time t1 is the time when the air conditioner is started, and at this stage, the temperature has already exceeded the concentration temperature. The calculating means 39 obtains the time t0 when the measurement result exceeds the concentration temperature, and obtains the temperature in the past temperature data at the time of t0. Next, a line is drawn from the temperature in parallel with the time axis, and the time t2 at the point where the data curve intersects is determined again. The time t2 is a time at which the temperature of the day does not require any further concentration, and can be estimated as the dilution time of the day.

The time width T is obtained by subtracting t1 from the time t2 obtained in this way, and is, in other words, a time for maintaining the concentration. Note that t2 can also be obtained by estimating that the temperature changes by taking a change curve substantially parallel to the past temperature change as shown by the two-dot chain line in FIG.

The control means 40 compares the reference time T0 stored in the second storage means 8 with the time width T obtained by the calculation means 39. When the time width T is longer than the reference time T0, it is determined that the absorption liquid is concentrated, the opening degree of the fuel supply control valve 15 is increased, the amount of generated refrigerant is increased, and the valve V5 is opened to condense the liquid. The refrigerant flows into the refrigerant tank 18.

On the other hand, when the time width T is shorter than the reference time T0, it is determined that the operation of concentrating the absorbing solution is not performed.
The cooling operation is continued with the concentration of the dilute solution as it is.

Next, the operation of the cooling cycle will be described with reference to FIG.

Before starting the operation, the valves V1, V3, V4, V5
Is closed and valve V2 is open. The dilute solution in the regenerator 12 is sent to the dilute solution tank 21 and is empty, and the refrigerant in the refrigerant tank 18 is sent to the dilute solution tank 21 while leaving a predetermined amount inside. Thus, the dilute solution in the dilute solution tank 21 is stored in a state of being mixed at a concentration that does not cause crystallization even at the lowest temperature.

When the operation button of the remote controller 6 is turned on,
Setting desired temperature, the valve V2 is closed with the valve opens V1, V3, V5 (F- 1), dilute solution from a dilute solution tank 21 by the motor M ₂ is driven pump 23 is sent to the regenerator 12 (F-2). Controller 30
Determines whether the liquid level of the regenerator 12 has reached a specified level by referring to a signal from the sensor T3 (F-3). If the liquid level has reached the specified level, the fuel supply The control valve 15 is opened to supply fuel gas from the fuel supply pipe 14, and the burner 13 is ignited (F-4).

When the regenerator 12 is heated, refrigerant vapor is generated from the stored dilute solution, and the refrigerant vapor is sent to the condenser 16 and the concentrated solution (absorbent) from which the refrigerant has been separated passes through the valve V1. To the absorber 20. Since the temperature of the condenser 16 gradually rises due to the inflow of the refrigerant vapor, the controller 30 operates the condenser 1 based on a signal from the sensor T4.
It is determined whether the temperature of No. 6 has reached a predetermined value (F-5),
When the predetermined value is reached, the air-cooling fan 17 is rotated (F-
6). As a result, in the condenser 16, the refrigerant vapor sent from the regenerator 12 is liquefied, and the liquefied refrigerant flows into the refrigerant tank 18 via the valve V5.

Next, it is determined whether the amount of refrigerant in the refrigerant tank 18 has reached a predetermined value by checking the signal from the sensor T6 (F-7), and when the amount has reached the predetermined value, the valve V5 is closed (F-7). -8), the fan 11 is rotated (F-9).
In addition, when the required amount of refrigerant for cooling is stored in the cooling tank 18 from the beginning and the absorption liquid is concentrated to a predetermined concentration, the cooling operation may be started immediately.

When the valve V5 is closed, the refrigerant in the condenser 16 flows into the evaporator 10 through the capillary 24, and the refrigerant evaporates (vaporizes) inside the evaporator 10, and a cooling action by heat of vaporization occurs. As a result, the air sent from the room through the intake duct 4 by the blower fan 11 is cooled by directly contacting the outer surface of the evaporator 10. The cooled air is sent to the indoor unit 2 through the air duct 3,
The air is blown out as cold air inside, and the chamber 5 is cooled (F-1).
0).

The refrigerant evaporated and vaporized in the evaporator 10 flows into the absorber 20, where it is absorbed by the absorbing liquid. The absorbent whose concentration has been reduced by absorbing the refrigerant once enters the dilute solution tank 21, passes through the valve V3 by the pump 23, and is discharged from the regenerator 12 by the heat exchanger 22 at a high concentration. It is exchanged and sent to the regenerator 12. This is the steady mode of the cooling operation. During this time, when the absorption liquid needs to be concentrated due to the rise in the outside air temperature, the valve V5 is opened accordingly, and the refrigerant flows into the refrigerant tank 18.

Next, the temperature and pressure of the container, the absorbing liquid, and the refrigerant in each part of the system during the cooling operation will be described.

Temperature (° C.) Pressure (Torr) Evaporator 10: 10-20 10-20 Regenerator 12: 60-90 90-110 Condenser 16: 50-80 90-110 Absorber 20: 45-50 11 Refrigerant tank 18: 30 to 50 40 to 50 Dilute solution tank 21: 40 to 60 11 Heat exchanger 22: 30 to 90-Intake duct 4: 26 (room temperature)-Blast duct 13 to 20-Dilute solution: 35 to 40 Concentration: 61% Concentrated solution: 90 Concentration: 64.8% Here, the concentration operation of the absorbing solution will be described in detail. The controller 30 is set in advance to a temperature at which the concentration operation is started. When the outside air temperature rises, the controller 30 determines whether or not to perform the concentration according to the flowchart shown in FIG.

First, the reference time T0 is input to the second storage means 8 (G-1). Then, the outside air temperature is input from the sensor T5 (G-2), and the temperature is sequentially stored in the first storage means 7 (G-3). Next, it is determined whether the temperature at the current time t1 has exceeded the concentration temperature (G-4), and if not, the process returns to (G-2). On the other hand, if the outside air temperature at the current time t1 exceeds the concentration temperature, or if the outside air temperature already exceeds the concentration temperature at the stage when the cooling start switch is turned on, the calculating means 39 sets the temperature to the past. Reference is made to the temperature data of (G-5) to obtain t2 (G-6). t2
Is the time at which the concentration of the absorbing solution will be diluted by a subsequent temperature change once the concentration of the absorbing solution has been concentrated. next,
T1 is obtained by subtracting t1 from t2 (G-7). This T
Is the operating time during which the operation is continued in a concentrated state when the solution is concentrated. When T is determined, the control means 40
Compares T with T0, and does not perform concentration if T is shorter than T0.

Therefore, even when the outside air temperature rises and reaches the concentration temperature at which the concentration of the absorbing solution should be concentrated, if it is judged that the time width required for the concentration of the absorbing solution is short, As a result, the concentration required is not increased because the loss required for the concentration exceeds the profit obtained by the increase in efficiency due to the concentration. This makes it possible to improve efficiency without wasting fuel. However, when the temperature reaches the concentration temperature, a strong cooling capacity is generally desired. Therefore, the opening degree of the fuel supply control valve 15 is increased, and the amount of combustion from the burner 13 is increased.
Increase the amount of refrigerant generated in the system. Then, the generated refrigerant is sent to the evaporator 10 without opening the valve V5 to increase the cooling.

On the other hand, when it is determined that T exceeds T0, a concentration operation is performed (G-9). This is because it has been determined that the time width required for concentration of the absorbing solution is sufficiently long. During that time, the efficiency is poor when the concentration of the absorbing solution is low. In that case, the loss required for the concentration of the absorbing solution is well compensated for by operating at high efficiency.

Returning to the flowchart of FIG. 3, when the operation button of the remote controller 6 is turned off (F-11), the process is terminated after performing the stop processing (F-12). As the stop processing, first, the burner 13 is extinguished, the valve V2 is opened, and
4 is opened by a required amount, a predetermined amount of refrigerant is left in the refrigerant tank 18, and the remainder is sent to the dilute solution tank 21. Then, the valve V1 is closed. Next, after a while, Pump 2
3 is stopped, the valve V3 is closed, and the blowing fan 11 and the air cooling fan 17 are stopped.

By doing so, the refrigerant tank 1
The refrigerant in 8 and the absorbent in regenerator 12 flow into dilute solution tank 21 and are diluted to a predetermined concentration. This is to prevent the refrigerant tank 18 and the regenerator 12 from being corroded by the absorbing liquid while the apparatus is stopped, to prevent crystallization of the dilute solution, and to maintain the concentration at a predetermined value. This makes it possible to immediately start the cooling operation the next morning or the like.

In the above embodiment, water is used as the refrigerant and lithium bromide is used as the absorbing liquid as in the conventional example. However, the present invention is not limited to this, and other similar functional materials may be used.

[0054]

According to the present invention, in an air conditioner using an absorption refrigerator, when the outside air temperature rises and the concentration of the absorbing liquid is concentrated to change the cooling capacity, the time width required for concentration is changed. In the case where the concentration is short, cooling was performed without intentionally performing concentration, so that an increase in fuel required for concentration and a decrease in cooling capacity during concentration operation can be avoided, and efficient operation can be performed during that time. Can be. On the other hand, when it is determined that the time width required for concentration is sufficiently long, concentration can be performed, whereby the overall efficiency can be increased. In this case, efficient cooling operation can be performed.

Since the outside air temperature change data used for estimating the temperature change is formed based on the past temperature change,
Control that always reflects unique conditions such as the installation status of the air conditioner and seasonal fluctuation conditions can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a main part of an embodiment of an air conditioner according to the present invention.

FIG. 2 is a block diagram of a main part of an embodiment of an air conditioner according to the present invention.

FIG. 3 is a flowchart of an air conditioner according to the present invention.

FIG. 4 is a graph showing a temperature change.

FIG. 5 is a flowchart of an air conditioner according to the present invention.

FIG. 6 is a block diagram illustrating an example of a conventional air conditioner.

FIG. 7 is a diagram illustrating an installation state of an air conditioner.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 outdoor unit 2 indoor unit 3 ventilation duct 4 air intake duct 5 room 6 remote controller 7 first storage means 8 second storage means 10 evaporator 11 blower fan 12 regenerator 13 burner 16 condenser 17 air cooling fan 18 refrigerant tank 20 absorption Container 21 Dilute solution tank 23 Pump 30 Controller 31 Communication controller 39 Operation means 40 Control means T1, T2, T3, T4, T5, T6 Sensor V1, V2, V3, V4, V5 Valve

Continuation of the front page (56) References JP-A-6-317361 (JP, A) JP-A-1-134178 (JP, A) JP-A-4-295558 (JP, A) JP-A-2-140562 (JP) JP-A-1-263468 (JP, A) JP-A-4-15441 (JP, A) JP-A-59-175938 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB Name) F24F 11/02 102

Claims (1)

(57) [Claims] 1. A regenerator for heating a dilute solution having a refrigerant absorbed in an absorbing liquid to generate refrigerant vapor and a concentrated absorbing liquid; a heater for heating the regenerator; A condenser for condensing the refrigerant vapor, a refrigerant tank for storing the condensed refrigerant, an evaporator for vaporizing the refrigerant sent from the condenser, and a refrigerant vapor for storing the absorption liquid and vaporized in the evaporator. An air-cooling fan that cools the absorber and the condenser together, a duct that has the evaporator therein, and has a suction port and an air outlet in the room, and the duct A cooling fan for introducing the room air to be cooled, which is directly cooled by the evaporator, and then blowing the cooled air into the room from the outlet, and a measuring means for measuring the outside air temperature And heating the heater to outside air Control in response to temperature changes,
An air conditioner using an absorption refrigerator configured to adjust the concentration of the absorbing solution, wherein: a first storage means for storing a past change in outside air temperature; When the time is reached, a calculation means for comparing the change in the past outside air temperature with the current outside air temperature to calculate a time width T in which the concentration of the absorbing solution needs to be concentrated, and a second storage means for storing a reference time T0 An air conditioner using an absorption refrigerator, comprising: a control unit for performing an operation of concentrating the absorption liquid when it is determined that the time width T is longer than the reference time T0.