JP3124686B2 - 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.

[0002]

2. Description of the Related Art Air conditioners using absorption chillers are currently used for industrial applications such as factories, buildings or large stores.
It is mainly used for commercial facilities.

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, the present inventors perform a cooling cycle operation in which the condenser and the absorber are cooled not by the water cooling system but by the air cooling system, and the air to be cooled is directly passed through the evaporator to be cooled instead of using the cooling medium. Proposing an air conditioner (Japanese Patent Application No. Hei 5)
-22351).

FIG. 4 shows an essential part of a modification of the air conditioner using the single-effect absorption refrigerator proposed in the above-mentioned application, and FIG. 5 shows an installation state of the air conditioner.

[0010] As shown in FIG.
The outdoor unit 1 is disposed outside the room 5 of the house to be air-conditioned by a configuration as shown in FIG. 4, and the indoor unit 2 has only the cool air outlet and the indoor 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. Reference numeral 6 denotes a remote controller for starting or stopping the operation of the apparatus, setting or canceling the automatic operation, setting the room temperature, and adjusting the amount of blown cold air.

The interior of the outdoor unit 1 has a configuration as shown in FIG. 4, in which an aqueous solution of lithium bromide is used as an absorbing solution, and water is used as a refrigerant.

The evaporator 10 has a function of evaporating the refrigerant and cooling the air passing therethrough by the latent heat of evaporation.
The air duct 3 and the intake duct 4 are connected. A blower fan 11 is provided in the intake duct 4.

The regenerator 12 has a function of generating refrigerant vapor by heating the absorption liquid having a low concentration by absorbing the refrigerant by the burner 13 and concentrating the absorption liquid. Fuel gas is supplied to the burner 13 from a fuel supply pipe 14, and the degree of combustion is adjusted by the opening of the fuel supply control valve 15.

The condenser 16 has a function of cooling and liquefying the refrigerant vapor sent from the regenerator 12 by an air-cooling fan 17, and converts a part of the refrigerant into the refrigerant in order to adjust the average concentration of the circulating solution. Store in the tank 18.

The absorber 20 stores the absorbing liquid, has a function of absorbing the refrigerant evaporated in the evaporator 10 into the absorbing liquid, and is air-cooled by the same air-cooling fan 17 as the condenser 16. The absorbent whose concentration has been lowered by absorbing the refrigerant is temporarily stored in the dilute solution tank 21.

Reference numeral 22 denotes a dilute solution tank 21 and a regenerator 12.
A heat exchanger 23 for performing heat exchange between a low-temperature absorbent having a low concentration and flowing toward the absorber 20 and a high-temperature absorbent having a high concentration flowing from the regenerator 12 to the absorber 20 absorbs the refrigerant and has a low concentration. A pump 24 for sending the absorbed liquid from the dilute solution tank 21 to the regenerator 12 is provided between the upstream side of the evaporator 10 and the condenser 16.
And a pressure loss member such as a capillary provided between the downstream side and the downstream side.

V1, V2, V3, V4, and V5 are control valves such as solenoid valves. Particularly, V4 has a check function that does not allow a dilute solution to flow from the dilute solution tank 21 to the refrigerant tank 18 side. It is a valve.

The above air conditioner basically controls each container by controlling the temperature of each container except that a pump 23 is used to send the absorbing liquid 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.

In this type of air conditioner, even when the operating condition is changed by a user's instruction or the operating condition is changed due to a change in the temperature of the outside air or the like, smooth and stable operation is performed according to the current situation. Continuation of the operation is required, and for that purpose, it is necessary to circulate the refrigerant stably under various conditions.

In this type of air conditioner, which uses a pump only for supplying the dilute solution to the regenerator and circulates the refrigerant itself by a pressure difference between various parts in the apparatus, the refrigerant is circulated stably regardless of the situation. In order to maintain a stable cooling capacity by performing the above, it is necessary to adjust the pressure of the condenser so as to maintain a predetermined pressure difference with respect to the evaporator having a preset pressure. Since the pressure of the condenser depends on the temperature of the condenser, the pressure of the condenser can be adjusted by adjusting the temperature of the condenser.

Therefore, the present inventors controlled the motor rotation speed of the air cooling fan for cooling the condenser in accordance with the temperature of the condenser, thereby stably sending the liquefied refrigerant from the condenser to the evaporator, and stabilizing the liquefied refrigerant. An air conditioner capable of exerting cooling capacity has been proposed (Japanese Patent Application No. 5-264296).

[0022]

By the way, in the above-mentioned air conditioner, if the PID control method well known in the art is used for controlling the motor speed of the air cooling fan for cooling the condenser, for example, Are vulnerable to external disturbances, the external air temperature and the fuel supply control valve 15
The controllability may be degraded due to a change in the gas supply amount according to the opening degree of the gas.

Therefore, it is conceivable to use modern control to cope with various load fluctuations. By the way, when designing an optimal regulator for modern control, for example, in the design of a control system by the state space method, all state variables must be freely available, but in reality, only the output can be measured by sensors etc. In addition, when the system is expressed by the equation of state, the state variables other than the output generally have no physical meaning, and these state variables are intermediate variables for expressing the dynamic relationship between the input and the output. It is not a variable that can be measured because it is only a simple measurement. For this reason, it is necessary to estimate the state variables in order to apply the state feedback, and there is a method of incorporating a state observer (observer) into the system proposed by Luenberger as an estimation method (“Introduction to Digital Control”, Nikkan Kogyo Newspaper company,
See pages 121-123).

This observer can be changed to have desired characteristics by designating the root of the characteristic equation (hereinafter also referred to as "eigenvalue"). For example,
When the absolute value of the eigenvalue approaches 0, the convergence of the control value to the target value becomes faster, but if there is noise in the input, it is sensitive to the noise, and thus has a disadvantage that it is weak to noise. . On the other hand, if the absolute value of the eigenvalue approaches 1, the noise becomes stronger but the convergence time becomes longer. Therefore, when an observer is incorporated in a system, the observer must have an eigenvalue that realizes characteristics desired for the system.

As described above, normally, good control can be performed by incorporating an eigenvalue observer that realizes a desired characteristic of the system. For example, in the case of controlling the number of rotations of a motor of an air-cooling fan for cooling a condenser of an air conditioner using an absorption refrigerator, the absolute value of the eigenvalue of the observer must be relatively high in order to quickly bring the temperature of the condenser close to a desired temperature. It must be close to 0, but on the other hand,
If the absolute value of the eigenvalue of the observer is too close to 0, if noise is included in the output of the temperature sensor that measures the outside air temperature or the temperature sensor that measures the condenser temperature, it will react too sensitively to the noise, On the contrary, the controllability deteriorates.

Although the eigenvalue of the observer is determined in consideration of such circumstances, when an air conditioner is actually installed, the environment and other installation conditions at the installation place are various, and the individual differences of the apparatus are also different. Therefore, there is a problem that good control is not performed in some cases.

The present invention has been made in view of the above points, and provides an air conditioner using an absorption refrigerating machine capable of controlling the pressure of a condenser satisfactorily irrespective of the installation conditions and individual differences of the device. The purpose is to:

[0028]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an evaporator for evaporating a refrigerant, an absorbing liquid for absorbing the refrigerant, and a refrigerant vapor evaporated by the evaporator for the absorbing liquid. An absorber for absorbing, a regenerator for heating the diluted absorbing liquid that has absorbed the refrigerant vapor to generate the refrigerant vapor and the concentrated absorbing liquid, and a condenser for condensing the refrigerant vapor generated by the regenerator, A refrigerant is sent from the condenser to the evaporator by the pressure difference between the condenser and the evaporator, and the air in the room to be air-conditioned by the evaporator is directly cooled. In an air conditioner using an absorption refrigerator that performs cooling by blowing air to the air conditioner, an air cooling fan that cools the condenser and a gas input detection unit that detects, as a gas input, an amount of gas burned by a burner that heats the regenerator A condenser temperature detecting means for detecting the temperature of the condenser, and a specified value as a unique value of the observer, and the rotation speed of the air-cooling fan, the outside air temperature and the gas input are inputted, and the condenser temperature is inputted. As an output, first storage means for storing parameters of an optimal regulator designed in advance, and specifying a value different from the predetermined value as an eigenvalue of the observer, and then rotating the air-cooling fan, the outside air temperature and the gas. A second storage means for storing an input of an input and the condenser temperature as an output and storing parameters of an optimal regulator designed in advance, and a good result based on a detection result by the condenser temperature detection means and a rotation speed of the air cooling fan. Control state determining means for determining whether or not control is being performed; and an optimal regulation normally stored in the first storage means. Calculating the rotation speed of the air-cooling fan using the parameters of the air-cooling fan, and when it is determined that the good control is not being performed by the control state determination means, the parameter of the optimal regulator stored in the second storage means is used. An air conditioner is constituted by a calculating means for calculating the rotation speed of the air cooling fan, and an air cooling fan driving means for driving the air cooling fan at the rotation speed calculated by the calculating means.

[0029]

According to the present invention, the first storage means and the second storage means are operated by the arithmetic means in accordance with the information as to whether or not the good control determined by the control state determination means is performed. The parameters of the optimal regulator designed using the observers having different eigenvalues stored in advance are switched and calculated, and the air-cooling fan driving means drives the air-cooling fan based on the calculation result.

[0030]

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

FIG. 1 shows an essential part of an embodiment of an air conditioner using a single-effect absorption refrigerator embodying the present invention. The installation state of the air conditioner according to the present invention is as shown in FIG.

The basic configuration of the air conditioner according to the present invention is the same as the configuration shown in FIG. 4, so that the description thereof will be omitted, and the electric circuit necessary for controlling the device will be mainly described.

T1 is a temperature sensor for detecting the indoor temperature provided on the upstream side of the evaporator 10, T2 is a temperature sensor for detecting the blast temperature, T3 is a level sensor for detecting the liquid level of the regenerator, and T4 is a condenser. Temperature sensor for detecting the outlet temperature of the vessel, T
Reference numeral 5 denotes a temperature sensor for detecting the outside air temperature.

The air conditioner includes a controller 30 including a CPU, a memory, and a drive circuit, and a remote controller 6 (FIG. 5).
) Is received by the receiving unit 2a of the indoor unit 2,
A communication controller 31 for receiving a signal from the receiving unit 2a is provided, and the controller 30 includes temperature sensors T1, T
2, signals from T4, T5 and level sensor T3;
Receiving the signal from the communication controller 31,
The operation of the air-cooling fan 17, the pump 23, and the fuel supply control valve 15 is controlled.

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

Before the start of operation, the valves V1, V3 and V5 are closed and the valves V2 and V4 are open. All of the absorbing liquid is in the dilute solution tank 21, and the regenerator 12 is empty.

When the start button of the remote controller 6 is turned on, the valves V1, V3, V5 are opened and the valves V2, V
4 is closed (F-1), the motor M ₂ is driven pump 2
3, the absorbing solution is sent from the dilute solution tank 21 to the regenerator 12 (F-2). At this time, C in the controller 30
The PU checks the signal from the level sensor T3 to determine whether or not the liquid level of the regenerator 12 has reached a specified level (F
-3). When the liquid level reaches a specified level, the fuel supply control valve 15 is opened to supply fuel gas from the fuel supply pipe 14 and ignite the burner 13 (F-4).

The refrigerant vapor is generated in the regenerator 12 and the condenser 16
And the temperature of the condenser 16 gradually rises due to the temperature of the refrigerant vapor. CPU in the controller 30 determines whether or not the temperature of the condenser 16 by a signal from the temperature sensor T4 has reached a predetermined value (F-5), the cooling fan 17 by the motor M ₁ is when it reaches a predetermined value (F-
6).

In the condenser 16, the vapor refrigerant sent from the regenerator 12 is liquefied, and the liquefied refrigerant flows into the refrigerant tank 18 via the valve V5. At this time, the CPU in the controller 30 determines whether or not the amount of the refrigerant in the refrigerant tank 18 has reached a predetermined amount (F-7). When the amount of the refrigerant has reached the predetermined amount, the valve V5 is closed (F-8). The fan 11 is rotated (F-9).

At this time, the refrigerant from the condenser 16 flows into the evaporator 10 via the capillary 24, and the refrigerant evaporates in the evaporator 10 and is sent from the room through the intake duct 4 by the blower fan 11 by the latent heat due to the latent heat. Cool the air. The cooled air is sent to the indoor unit 2 through the air duct 3 and is blown out as cold air into the room 5 to cool the room 5 (F-10).

In this cooling operation, the refrigerant evaporated and vaporized in the evaporator 10 flows into the absorber 20, where it is absorbed by the absorbing liquid. The absorption liquid whose concentration has been reduced by absorbing the refrigerant once enters the dilute solution tank 21 and is then pumped.
Is exchanged with the high-concentration high-temperature absorbent discharged from the regenerator 12 in the heat exchanger 22 through the valve V3. This state is the steady mode of operation.

When the start button of the remote controller 6 is turned off (F-11), a stop process is performed (F-12), and the process ends. In the stop processing, first, the burner 13 is extinguished, the valves V2 and V4 are opened, and the valve V1 is closed. Next, after a while, the pump 23 is stopped, the valve V3 is closed, and the blower fan 11 and the air cooling fan 17 are stopped. By doing so, the refrigerant in the refrigerant tank 18 and the regenerator 1
All of the absorption liquid in 2 flows into the dilute solution tank 21. This is because while the device is stopped, the refrigerant tank 1
8 and the regenerator 12 to prevent corrosion and dilute the concentrated solution to prevent crystallization.

Next, an air conditioner using an absorption refrigerator is
Control according to the present invention for continuing smooth and stable operation according to the situation at that time will be described.

In the present embodiment, first, when creating a servo system model for controlling the outlet temperature of the condenser 16,
The outside air temperature detected by the temperature sensor T5, the amount of supply gas according to the opening of the fuel supply control valve 15 (hereinafter referred to as "gas input"), and the motor M for rotating the air cooling fan 17
The rotation speed of ₁ is input, and the outlet temperature of the condenser 16 detected by the temperature sensor T4 is modeled as an output. An example of this model is shown in Equation 1.

[0045]

[Number 1] _{y (t) + a 1 ·} y (t-1) + a 2 · y (t-2) = b 0 · u b (t) + b 1 · u b (t-1) + b _{2 · u b (t-2} ) + c 0 · u c (t) + c 1 · u c (t-1) + c 2 · u c (t-2) + d 0 · u d (t) + in _{d 1 · u d (t-} 1) + d 2 · u d (t-2) number _{1, u b (t),} u c (t), u d (t)
Are inputs corresponding to the outside air temperature, the gas input, and the number of rotations of the air-cooling fan, respectively, y (t) is an output corresponding to the condenser outlet temperature, and t is the time when sampling is performed in time series. This is the sample number. The model order is second order.

These input / output values can be obtained by operating the air conditioner so that each input value is close to the value in the actual operating environment, and measuring each value at predetermined time intervals.

Equation 1 is an ARX model in which the delay of the system is 0. Here, the ARX model is a discrete-value model that assumes that the input and output of the system to be controlled have a time-series relationship as shown in Equation 1.

Next, by converting the time series model of Equation 1 into a matrix expression (state space type), a state equation of Equation 2 and an output equation of Equation 3 are established.

[0049]

X (t + 1) = AｔX (t) + BU ・ (t)

[0050]

Y (t) = C ・ X (t) + DU ・ (t) In Equations 2 and 3, U (t) is an input, Y (t) is an output, and X (t) is a state variable. is there.

The input U (t) in Equations 2 and 3
(In this embodiment, the outside air temperature, the gas input, and the number of rotations of the air-cooling fan are combined into one matrix.) The output Y (t) (in this embodiment, the condenser outlet temperature) and X (1) are Once obtained, the coefficients A, B, C, and D of the above state equation and output equation can be calculated. Calculating the coefficients A, B, C, and D and formulating the relationship between the input and the output in this manner is called system identification.

FIG. 3 is a state variable diagram of the servo system of the air conditioner according to the present invention, which is modeled as shown in Equations 1 to 3.

In FIG. 3, 35 is a servo system to be controlled, 36 is an additional integrator realized by the CPU in the controller 30 shown in FIG. 1, and 37 is an observer. U (k) is the number of rotations of the air-cooling fan which is an input to the control target, x (k) is a state variable, y (k) is the temperature at the outlet of the condenser 16 measured by the temperature sensor T4, r (k) Is condenser 1
6, a target value of the outlet temperature, e (k) is a difference obtained by subtracting a measured value from a target value of the outlet temperature of the condenser 16, and z (k) is a measured value of the target value of the outlet temperature of the condenser 16. Is the integral value of the difference obtained by subtracting.

The observer 37 has an input u (k) and an output y
(K) and a state variable x (k) is derived and fed back. The eigenvalue of the observer 37 is set to a predetermined value such that the value to be controlled converges to the target value within a predetermined time.

In order to realize the control of the state variable diagram shown in FIG. 3, it is necessary to obtain the feedback gains F ₁ and F ₂ . Therefore, next, a method of obtaining the feedback gains F ₁ and F ₂ will be described.

The feedback gains F ₁ and F ₂ are
It is obtained by evaluating the state equation of Equation 2 and finding an optimal solution. Equation 4 is a quadratic form evaluation function serving as an index of this evaluation.

[0057]

(Equation 4) In Equation 4, X ^T and U ^T are transposes of matrices X and U, respectively, and Q and R are weight matrices.

Optimum control is to determine the control input U so as to minimize the value J of the evaluation function shown in equation (4).
An increase in the weight matrix Q results in an increase in the responsiveness of X, while an increase in the weight matrix R results in a decrease in the control input U. In designing an optimal regulator, a designer determines weight matrices Q and R in advance based on the responsiveness required for the system, input restrictions, and the like.

As described above, the value J of the evaluation function shown in Expression 4 is obtained.
Is obtained, the feedback gains F ₁ and F ₂ can be obtained.

In this embodiment, feedback gains F ₁ and F ₂ are obtained by setting C = [1,0] and D = 0 in the output equation of Expression 3. The feedback gains F ₁ and F ₂ are obtained in advance as described above, and stored in the memory of the controller 30 in advance. The memory in which the feedback gain is stored in advance is preferably a non-volatile memory (for example, a ROM) that does not lose its stored contents even if power is not supplied to the air conditioner.

When controlling the temperature at the outlet of the condenser 16, the rotation speed of the air-cooling fan is obtained by the equation 5, and the air-cooling fan 17 is rotated at this rotation speed.

[0062]

(Equation 5) In the equation (5), (r (t) -y (t)) is the condenser 1
6 is a difference obtained by subtracting the actually measured value from the target value of the outlet temperature, that is, e (t).

As described above, by controlling the rotation speed of the air-cooling fan 17 of the air conditioner and adjusting the temperature of the outlet of the condenser 16, control by the optimum regulator can be realized.

As described above, the feedback gains F ₁ and F ₂ are gains obtained by using a predetermined value as a characteristic value of the observer 37 so that the value to be controlled converges to the target value within a predetermined time. It is. However, when an air conditioner is actually installed, the environment and other installation conditions at the installation site are various, and there are individual differences between the devices, so that good control may not be performed in some cases.

Therefore, in the air conditioner according to the present invention, a plurality of types of feedback gains obtained using observers having different eigenvalues are further prepared in advance and stored in the memory in the controller 30 in advance.

For example, a feedback gain F obtained by using an observer having a predetermined value as an eigenvalue so that the value to be controlled converges to a target value within a predetermined time.
₁ and other F _2, further, the predetermined value than the advance determined in the same manner the feedback gain F ₃ and F ₄ using the eigenvalues of the observer close to 0, the controller 30 of the two sets of feedback gain It is stored in the memory in advance.

When controlling the temperature at the outlet of the condenser 16, the feedback gains F ₁ and F ₂ are usually used.
Are stored in a time-series manner, and the temperature at the outlet of the condenser 16 detected by the temperature sensor T4 and the number of rotations of the air-cooling fan 17 are stored in a time-series manner. (Whether the value to be controlled converged to the target value within a predetermined time). If it is determined that good control is not being performed, the feedback gain in Equation 5 is changed to gains F ₃ and F ₄ . The air-cooling fan 17 is rotated at the air-cooling fan rotation speed obtained by the above.

In the present embodiment, the optimal regulator is designed using the ARX model. However, it may be calculated using the least squares method or the prediction error method using another model.

Further, in the present embodiment, although the aqueous solution of lithium bromide is used as the absorbing solution and water is used as the refrigerant, the present invention is not limited to this, and can be applied to, for example, a case where ammonia is used as the refrigerant. .

[0070]

As described above, according to the present invention,
It is possible to control the pressure of the condenser satisfactorily irrespective of the installation conditions of the apparatus and individual differences. That is, by controlling the pressure of the condenser, stable circulation of the refrigerant can be performed, and stable cooling capacity can be maintained.

[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 shows a flowchart of a steady mode of operation of the air conditioner according to the present invention.

FIG. 3 is a state variable diagram of a servo system of an air conditioner according to the present invention, which is modeled as shown in Equations 1 to 3.

FIG. 4 is a block diagram of a main part of a modification of an air conditioner using a single-effect absorption refrigerator proposed in the prior application.

FIG. 5 shows an installation state of the air conditioner shown in FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 outdoor unit 2 indoor unit 3 air duct 4 air intake duct 5 room 6 remote controller 10 evaporator 11 air fan 12 regenerator 13 burner 14 fuel supply pipe 15 fuel supply control valve 16 condenser 17 air cooling fan 18 refrigerant tank 20 absorber 21 dilute solution tank 30 controller 31 communication controller 35 servo system 36 adds the integrator 37 observer T1, T2, T4, T5 temperature sensor T3 level sensor V1, V2, V3, V4, V5 valve M _1, M ₂ motor

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-1-260268 (JP, A) JP-A-2-259373 (JP, A) JP-A-4-86463 (JP, A) JP-A-6-260 2927 (JP, A) JP-A-8-29005 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00 306

Claims (4)

(57) [Claims] 1. An evaporator for evaporating a refrigerant, an absorber for storing an absorbing liquid for absorbing the refrigerant and absorbing the refrigerant vapor evaporated by the evaporator to the absorbing liquid, and heating the rare absorbing liquid having absorbed the refrigerant vapor. And a condenser for condensing the refrigerant vapor generated in the regenerator, and a condenser for condensing the refrigerant vapor generated in the regenerator, wherein a pressure difference between the condenser and the evaporator causes the condenser to evaporate from the condenser. An air conditioner using an absorption refrigerator that sends a refrigerant to the evaporator, directly cools room air to be air-conditioned by the evaporator, and blows the cooled air into the room through a duct to perform cooling. An air-cooling fan that cools the condenser, a gas input detector that detects, as a gas input, an amount of gas burned by a burner that heats the regenerator, and a condenser temperature detector that detects a temperature of the condenser. After designating the predetermined value as a characteristic value of the observer, the rotation speed of the cooling fan, and inputs the outside air temperature and the gas input, as an output the condenser temperature, the first for storing parameters of the optimal regulator with predesigned
After designating a value different from the predetermined value as a unique value of the observer, the rotational speed of the air-cooling fan, the outside air temperature and the gas input are input, and the condenser temperature is output as an output. Second storage means for storing parameters of the optimal regulator; control state determining means for determining whether desired control is being performed based on a result detected by the condenser temperature detecting means and the number of revolutions of the air cooling fan; Normally, the rotation speed of the air-cooling fan is calculated using the parameters of the optimal regulator stored in the first storage means, and when the control state determination means determines that the desired control is not being performed, the second control is performed. Calculating means for calculating the number of revolutions of the air-cooling fan using the parameters of the optimal regulator stored in the storing means, An air-conditioning apparatus comprising: an air-cooling fan driving unit that drives the air-cooling fan at the calculated rotation speed. 2. The control state determining unit determines whether desired control is being performed based on whether a result of detection by the condenser temperature detecting unit has converged to a target value within a predetermined time. Item 2. The air conditioner according to item 1. 3. The air conditioner according to claim 1, wherein the condenser temperature detecting means detects a temperature at an outlet of the condenser. 4. The air conditioner according to claim 1, wherein said first storage means and said second storage means are nonvolatile storage means.