JP3124662B2 - 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 to an air conditioner capable of maintaining good 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. 5 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 is disposed outside the room 5 of the house to be air-conditioned by a configuration as shown in FIG. 5, 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. 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. 5, 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). I am going to receive it.

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
The fuel gas is supplied from the fuel supply 4, and the degree of combustion is adjusted by 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 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 the valve 5.

The absorber 20 stores the absorbing liquid, has a function of absorbing the refrigerant evaporated by 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 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 the pressure difference between the containers and the temperature difference except that a pump 23 is used to send the absorbent from the absorber 20 to the regenerator 12. The refrigerant is sent out and circulated by the pressure difference.

[0020]

By the way, in such an air-cooled air conditioner, when the air volume sent from the air duct is automatically changed in order to keep the indoor environment faithful to the set desired conditions. Or, the user may arbitrarily reduce the air volume. When the amount of air blown is changed in this way, the amount of heat of the evaporator taken away by this airflow decreases, and a phenomenon occurs in which some of the refrigerant passing through the evaporator flows into the absorber as a liquid without being evaporated. appear. Then, there is a problem that operation in an optimal state cannot be performed and efficiency is deteriorated.

The present invention has been made in view of the above points, and has an evaporator for evaporating a refrigerant, an absorbing liquid for storing an absorbing liquid for absorbing the refrigerant, and absorbing the vaporized refrigerant vaporized by the evaporator to the absorbing liquid. An evaporator is disposed in a passage for introducing room air to be cooled, and the room air is directly cooled, and then the cooled air is directly blown into the room through a duct to perform cooling. In an air conditioner using a refrigerator, even when the required amount of refrigerant in an evaporator is reduced, such as when the amount of air flowing into a room is reduced, the evaporator does not generate unevaporated refrigerant and can always operate with high efficiency. The purpose is to be.

[0022]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an evaporator for evaporating a refrigerant, an absorbent for absorbing the refrigerant, and a refrigerant vapor vaporized by the evaporator for absorbing the refrigerant. The evaporator is disposed in a passage for introducing indoor air to be cooled, and the indoor air is directly cooled, and then the cooled air is directly blown into the room through a duct to perform cooling. In the air conditioner using an absorption refrigerator that performs, a blower installed in the passage or the duct, a regenerator that heats the absorption liquid to generate refrigerant vapor from the absorption liquid, and heats the regenerator A burner, first and second detecting means provided on each of a refrigerant inlet side and an outlet side of the evaporator to detect the refrigerant temperature,
Storage means for storing a temperature difference between the detected temperatures of the first and second detection means in a steady operation state;
Control means for controlling a fuel supply amount of the burner such that a temperature difference of a detected temperature of the detection means is obtained and the temperature difference is within an allowable value of a reference temperature difference stored in the storage means. Thus, an air conditioner using a refrigerator was constructed.

[0023]

When more refrigerant is sent to the evaporator than is required for cooling in the evaporator, some of the refrigerant flows into the absorber as a liquid without being evaporated by the evaporator. Refrigerant, which remains liquid,
Since the temperature does not decrease due to evaporation, the temperature is high and the temperature at the outlet side of the evaporator rises, and the temperature difference between the inlet and outlet of the evaporator becomes small. You can judge that you have done. Therefore, when the temperature difference between the inlet side and the outlet side becomes smaller than the reference temperature difference in the steady operation state, the heating amount of the evaporator may be adjusted to approach the reference temperature difference. Thus, the amount of refrigerant generated in the regenerator is adjusted, and an appropriate amount of refrigerant is sent to the evaporator. Therefore, the excess refrigerant is supplied to the evaporator, the refrigerant does not flow into the absorber without being evaporated, and the efficiency of the air conditioner does not decrease.

[0024]

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

FIG. 3 shows a main part of an embodiment of an air conditioner using a single-effect absorption refrigerator embodying the present invention, and FIG.
The installation state of the air conditioner according to the present invention is shown as in the conventional example.

The mechanical structure of the air conditioner according to the present invention is shown in FIG.
Therefore, the description thereof is omitted, and the electric circuit necessary for controlling the air conditioner will be described.

In FIG. 3, T1 is a sensor for detecting the refrigerant temperature provided on the pipe surface on the inlet side of the evaporator 10,
2 is a sensor for detecting the temperature of the refrigerant provided on the pipe surface on the outlet side of the evaporator 10, T3 is a sensor for detecting the indoor temperature provided on the upstream side of the evaporator 10, T4 is a sensor for detecting the blast temperature, , T5 are sensors for detecting the liquid level of the regenerator, and T6 is a sensor for detecting the condenser temperature.

The controller 30 including a CPU, a memory, and a drive circuit, and a setting signal from the remote controller 6 (see FIG. 6) are received by the receiving unit 2a of the indoor unit 2, and the receiving unit 2a
And a communication controller 31 for receiving signals from the sensors T3, T4, T5, and T6.
And a signal from the communication controller 31 to control the operations of the blower fan 11, the air-cooling fan 17, and the pump 23.

Further, as shown in FIG. 1, the controller 30 has a control means 3 for adjusting the amount of gas supplied to the burner 13.
5 and storage means 36 and the like. Control means 35
Is connected to the sensors T1 and T2 and the storage means 36. In the storage means 36, the temperature difference between the sensors T1 and T2 when the air conditioner is operating in an optimum state is stored as a reference temperature difference. ing. The control means 35 calculates the temperature difference between the temperature t1 of the refrigerant on the inlet side of the evaporator 10 from the sensor T1 and the temperature t2 of the refrigerant on the outlet side from the sensor 2. Enter those temperature differences when operating in and compare these,
When a difference between the two is greater than the allowable value, the fuel supply control valve 15 for controlling the heating amount of the regenerator 12, that is, the fuel supply amount to the burner 13, is controlled.

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

Before starting operation, the valves V1, V3 and V5 are closed and the valve V2 is open. The regenerator 12 is empty.

When the operation button of the remote controller 6 is turned on,
Desired temperature, or by setting the desired air volume, the valve opens V3 (F-1), the absorption liquid from the dilute solution tank 21 by the motor M ₂ is driven pump 23 is sent to the regenerator 12 (F-2) . Other valves remain as they are. At this time, the CPU of the controller 30 determines whether or not the liquid level of the regenerator 12 has reached a prescribed level by looking at the signal from the sensor T5 (F-3). When the liquid level has reached the prescribed 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 increases. The CPU of the controller 30 uses the signal from the sensor T6 to
It is determined whether the temperature of No. 6 has reached a predetermined value (F-5),
When the predetermined value is reached, the valve V1 is opened, the valve 2 is closed (F-6), and the blower fan 11 and the air cooling fan 17 are rotated (F-7). As a result, the refrigerant vapor sent from the regenerator 12 is liquefied in the condenser 16, and the liquefied refrigerant is vaporized by the pressure difference between the condenser 16 and the evaporator 10.
Flows into. The refrigerant evaporates (vaporizes) inside the evaporator 10, and a cooling action by the 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 outside of the evaporator 10. 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-8).

In this cooling operation, the refrigerant evaporated in the evaporator 10 and turned into vapor flows into the absorber 20, where it is absorbed by the absorbing liquid. The absorbent whose concentration has decreased by absorbing the refrigerant once enters the dilute solution tank 21 and then exchanges heat with the high-concentration high-temperature absorbent which is sent from the regenerator 12 by the heat exchanger 22 through the valve V3 by the pump 23. And regenerator 1
It is sent to 2. This is the steady mode of the cooling operation. During this time, the valve V5 is repeatedly opened and closed as needed.

Here, control of the amount of generated refrigerant when the amount of air blown by the blower fan 11 is reduced will be described with reference to the flowchart of FIG.

First, the storage means 36 stores a reference temperature difference TB between the temperatures of the sensors T1 and T2 when the air conditioner is operating in an optimal state (G-
1). Next, it is determined whether or not the operation switch is off. If not, the temperature t1 on the inlet side of the evaporator 10 is detected from the sensor T1.
And the temperature t2 on the outlet side of the evaporator 10 from the sensor T2 (G-2).

Then, the temperature difference TA is obtained by subtracting t2 from t1 (G-3), and is compared with the reference temperature difference TB of the storage means 36 to determine whether or not the difference is within an allowable value (G-G).
5) If it is within the permissible range, return to G-2. If it exceeds the permissible range, proceed to G-6 and operate the fuel supply control valve 15 to lower the fuel supply amount by one step. 2
And the process is circulated. When it is determined in G-2 that the operation switch is off, the process ends.

Specifically, for example, in the automatic operation, the indoor temperature t3 detected by the sensor T3 is equal to the indoor set temperature t0.
, Or when the user inputs or sets the air volume from the remote controller 6 or the like so as to reduce the air volume, the output of the blower fan 11 becomes the indoor temperature t3 and the set temperature t0. Automatically or forcibly in accordance with the set value input by the user, and the airflow into the room is reduced. Then, the intake duct 4
Only a small amount of air passes through and the amount of air that comes into contact with the evaporator 10 decreases, and the evaporator 10 cools, that is, the amount of heat absorbed by the evaporator 10 decreases, and the cooling capacity of the evaporator 10 becomes excessive. become. Even if the refrigerant is sent to the evaporator 10 as it is, all of it does not evaporate, and the refrigerant flows into the absorber 20 as a liquid, and the efficiency is significantly reduced.

As described above, when the refrigerant flows into the absorber 20 without being evaporated inside the evaporator 10, the refrigerant temperature detected by the sensor T2 increases because the temperature of the flowing refrigerant remains high. Temperature t1 detected by sensor T1
And the difference is smaller. Therefore, the temperature difference TA between the temperatures t1 and t2 is monitored, and when the temperature difference TA decreases by more than an allowable range from the reference temperature difference TB in the optimal operation state, the refrigerant in the evaporator 10 becomes excessive. It is determined that the fuel supply has fallen, and the fuel supply amount of the fuel supply control valve 15 is reduced in order to reduce the heating amount of the regenerator 12. This fuel adjustment is performed until the temperature difference TA between t1 and t2 is within an allowable range as compared with the reference temperature difference TB.

Therefore, the fuel in the burner 13 is controlled so that only the required amount of refrigerant is always generated without generating excess refrigerant in the regenerator 13 and sending it to the evaporator 10, so that fuel consumption is reduced. The amount and the required amount of refrigerant can be made equal, and the air conditioner can be operated efficiently.

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% Then, returning to the flowchart of FIG. 4, when the operation button of the remote controller 6 is turned off (F-9), the blowing fan 1
1. The air-cooling fan 17 stops (F-10), during which the refrigerant in the refrigerant tank 18 and the absorbing liquid in the regenerator 12 all flow into the dilute solution tank 21. This is to prevent the refrigerant tank 18 and the regenerator 12 from being corroded by the absorbing liquid while the apparatus is stopped, or to dilute the concentrated solution to prevent crystallization. After a short time delay, the pump 23 stops (F-11), and the flow of all liquids in the entire system stops.

As described above, according to the air conditioner of the present embodiment, even when the required amount of refrigerant in the evaporator 10 decreases, such as when the air volume of the blower fan 11 decreases,
The difference between the temperature on the inlet side and the temperature on the outlet side of the evaporator 10 is monitored, and the combustion amount of the burner 13 is controlled so that the difference becomes a reference temperature difference, and the amount of refrigerant generated in the regenerator 12 is adjusted. Therefore, the refrigerant does not flow into the evaporator 10 and the refrigerant remains in the liquid state, and the air conditioner can be efficiently operated.

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 substances may be used.

[0044]

As described above, according to the present invention,
In an air conditioner using an absorption refrigerator, when the required amount of refrigerant in an evaporator is reduced, such as when the amount of blown air is reduced,
The difference between the inlet temperature and the outlet temperature of the evaporator is determined, and this temperature difference is compared with the reference temperature difference in an optimal operating condition. Since the amount of refrigerant generated in the regenerator is reduced by reducing the supply amount, there is no excess refrigerant generated in the regenerator and sent to the evaporator. Is prevented from flowing into the absorber as a liquid, and the air conditioner can always be operated with high efficiency.

[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 flowchart of an air conditioner according to the present invention.

FIG. 3 is a block diagram of a main part of an embodiment of an air conditioner according to the present invention.

FIG. 4 is a flowchart of a normal mode of operation of the air conditioner according to the present invention.

FIG. 5 is a block diagram illustrating an example of a conventional air conditioner.

FIG. 6 is a diagram illustrating an installation state of an air conditioner.

[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 16 condenser 17 air cooling fan 18 refrigerant tank 20 absorber 21 dilute solution tank 30 controller 31 communication control Instrument 35 Control means 36 Storage means T1, T2, T3, T4, T5, T6 Sensor V1, V2, V3, V4, V5 Valve

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-196464 (JP, A) JP-A-58-175769 (JP, A) JP-A-59-173666 (JP, A) JP-A-6-197666 272986 (JP, A) JP-A-7-98164 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00 306

Claims (2)

(57) [Claims] 1. An evaporator for vaporizing a refrigerant, and an absorber for storing an absorbing liquid for absorbing the refrigerant and absorbing the refrigerant vapor vaporized by the evaporator to the absorbing liquid, and introducing indoor air to be cooled. An air conditioner using an absorption refrigerator that cools the room air by arranging the evaporator in a passage and directly blowing the cooled air into a room through a duct to cool the room air. Determining a difference between the inlet side temperature and the outlet side temperature of the regenerator for reducing the heating amount of the regenerator for separating the refrigerant from the absorbing liquid when the temperature difference is equal to or less than a predetermined value. Air conditioner using absorption chiller. 2. An evaporator for vaporizing a refrigerant, and an absorber for storing an absorbing liquid for absorbing the refrigerant and absorbing the refrigerant vapor vaporized by the evaporator to the absorbing liquid, and introducing indoor air to be cooled. In the air conditioner using an absorption refrigerator that cools the room air by directly arranging the evaporator in the passage to cool the room air and then blowing the cooled air directly into the room through the duct, the passage or A blower installed in the duct, a regenerator that heats the absorbent and generates refrigerant vapor from the absorbent, a burner that heats the regenerator, and a refrigerant inlet side and an outlet side of the evaporator, respectively. First and second detecting means provided for detecting the refrigerant temperature;
Storage means for storing a temperature difference between the detected temperatures of the first and second detection means in a steady operation state;
Control means for obtaining a temperature difference of the detected temperature of the detection means, and controlling the fuel supply amount of the burner so that the temperature difference is within an allowable value of the reference temperature difference stored in the storage means. An air conditioner using an absorption refrigerator.