JP3118124B2 - 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 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, 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. A patent application has already been filed for an air conditioner (Japanese Patent Application No. Hei 5-22351).

[0009]

In this air-cooled air conditioner, the piping from the condenser to the refrigerant tank is branched into two systems, one of which is connected to the refrigerant tank from the condenser and the other of which is evaporated from the condenser. Communicates directly with the vessel. A valve is provided in a pipe directly communicating from the condenser to the refrigerant tank. This valve is opened when the solution is concentrated to increase the solution concentration, such as when the air conditioner starts up, and controls to store the refrigerant in the refrigerant tank. However, in the state where the valve on the opposite side of the refrigerant tank, that is, the valve between the refrigerant tank and the dilute solution tank, is closed, the refrigerant tank approaches a sealed state, and the temperature and the pressure maintain an equilibrium state, When the temperature of the refrigerant from the condenser increases, the pressure in the refrigerant tank also increases, making it difficult to obtain a pressure difference from the condenser. As a result, there is a problem that the refrigerant is not sent out from the condenser to the refrigerant tank, the refrigerant accumulates in the condenser, and finally the liquid level of the regenerator reaches the upper limit and the air conditioner stops.

The present invention has been made in view of the above points, and has been made so that the pressure inside the refrigerant tank is kept in equilibrium with the pressure of the evaporator during the concentration of the refrigerant. It is an object of the present invention to provide an air conditioner using an absorption refrigerator capable of storing a predetermined amount of refrigerant in a tank.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is to generate a refrigerant vapor by heating a dilute solution obtained by absorbing water as a refrigerant in an absorbent mainly composed of an aqueous solution of lithium bromide. A regenerator, a condenser for condensing refrigerant vapor generated in the regenerator by air cooling, and a condenser arranged in a duct through which air to be air-conditioned flows and connected to the condenser via a pressure loss member such as a capillary. An evaporator, an air-cooled absorber that inputs an absorbing liquid that absorbs the refrigerant evaporated by the evaporator, and a refrigerant tank that is connected to the condenser via a valve. In order to balance the internal pressure with the pressure of the evaporator, a passage portion directly connecting the refrigerant tank and the evaporator is provided.

[0012]

According to the present invention, in the process of concentrating a refrigerant, the pressure in the refrigerant tank also decreases in the process of concentrating the refrigerant, and the pressure in the condenser is balanced with the pressure in the evaporator, and the refrigerant is sent from the condenser to the refrigerant tank. Can be.

[0013]

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, and FIG. 2 shows an installed state of an air conditioner according to the present invention.

As shown in FIG. 2, the air conditioner according to the present invention comprises an outdoor unit 1 and an indoor unit 2, and the outdoor unit 1 is provided outside the room 5 of the house to be air-conditioned by the configuration shown in FIG. The indoor unit 2 has only the outlet for the cool air and the inlet for the indoor air, and is arranged inside the room 5. The outdoor unit 1 and the indoor unit 2 are composed of a cool air blowing duct 3 and a room air intake duct 4.
And are connected by. Reference numeral 6 denotes a remote controller for starting or stopping the operation of the apparatus, setting the indoor temperature to a desired temperature, and adjusting the amount of cool air to be blown.

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

The evaporator 10 is disposed at the junction of the ventilation duct 3 and the intake duct 4 communicating with the indoor unit 2 at the portion where the room air to be air-conditioned circulates, evaporates the refrigerant, and passes through it by the latent heat of evaporation. It has a function of cooling air and is connected to the condenser 16 via a pressure loss member such as a capillary 24. 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 reduced concentration by absorbing the refrigerant by the burner 13 and concentrating the concentration of 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 a combustion 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 a part of the refrigerant is transferred to a refrigerant tank 18 in order to adjust the concentration of the solution. store. The refrigerant tank 18 is connected to the condenser 16 via a valve V5.

In order to balance the pressure inside the refrigerant tank 18 with the pressure of the evaporator 10 in the process of concentrating the refrigerant, a passage 25 is provided which directly connects the refrigerant tank 18 and the evaporator 10.

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 absorption liquid whose concentration has been reduced 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 that performs heat exchange between a low-temperature absorbent having a low concentration toward the regenerator 12 and a high-temperature absorbent having a high concentration traveling from the regenerator 12 to the absorber 20 absorbs the refrigerant and decreases the concentration. The absorbed liquid is transferred from the dilute solution tank 21 to the regenerator 12
Is a pressure loss member such as a capillary provided between the upstream side of the evaporator 10 and the downstream side of the condenser 16.

V1, V2, V3, V4, V5 are valves, and especially V4 is a valve having a check function.

The above components are arranged as shown.

Next, an electric circuit for controlling the operation of the air conditioner will be described.

T1 is a sensor for detecting the 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, T4.
Is a sensor for detecting the condenser temperature.

A controller 30 including a CPU, a memory, and a driving circuit, a communication controller 31 that receives a setting signal from the remote controller 6 (see FIG. 2) at the receiving unit 2a of the indoor unit 2 and receives a signal from the receiving unit 2a. Is provided, and the controller 30 receives signals from the sensors T1, T2, T3, and T4,
Receiving the signal from the communication controller 31,
The operation of the air-cooling fan 17, the pump 23, and the fuel control valve 15 of the fuel supply pipe 14 is controlled.

Next, an example of 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 valve V2 is open. The regenerator 12 is empty.

When the operation button of the remote controller 6 is turned on, the valve V3 is opened (F-1), the motor M2 is driven, and the absorbing solution is sent from the dilute solution tank 21 to the regenerator 12 by the pump 23 (F-2). ). Other valves remain as they are. At this time, the CPU of the controller 30 is connected to the sensor T4.
It is determined whether or not the liquid level of the regenerator 12 has reached a specified level by looking at the signal from (F-3). When the liquid level has reached the specified level, the fuel 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 T4 to
It is determined whether the temperature of No. 6 has reached a predetermined value (F-5),
When the predetermined value is reached, the valves V1 and V5 are opened and the valve V2 is closed (F-6), and the blower fan 11 and the air cooling fan 17 are rotated (F-7). As a result, the regenerator 12
When refrigerant vapor sent from is liquefied and V5 is open,
Flows into the refrigerant tank 18 (which is air-cooled by the air-cooling fan 17 at this time), but flows into the evaporator 10 through the capillary 24 when V5 is closed. Thereby, the air sent from the room through the intake duct 4 by the blower fan 11 is cooled. The cooled air is sent to the indoor unit 2 through the air duct 3 and is blown out into the room 5 as cold air.
The room 5 is cooled (F-8).

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 then the pump 2
3, heat exchange with the high-concentration high-temperature absorbing liquid sent out of the regenerator 12 through the valve V3 and the heat exchanger 22;
It is sent to the regenerator 12. This state is the steady mode of operation. During this time, if concentration of the solution is necessary, the valve V5 is repeatedly opened and closed.

Here, the temperature and pressure of the container, the absorbing liquid, and the refrigerant in each part of the system during the cooling operation are exemplified as follows.

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: 35 to 40-Intake duct 4: 26-Blast duct 3: 13 to 20-Dilute solution: 35 to 40 Concentration : 61% concentrated solution: 90 concentration: 64.8% When the operation button of the remote controller 6 is turned off (F-9), the blower fan 11 and the air cooling fan 17 are stopped (F-1).
0), during which the refrigerant in the refrigerant tank 18 and the regenerator 12
Usually, all of the absorbing solution flows 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. The pump 23 stops after a short time delay (F-1).
1) The flow of all liquids in the entire system stops.

[0034]

As described above, according to the present invention,
Since a passage section directly connecting the refrigerant tank and the evaporator was provided,
During the concentration of the solution, the refrigerant is accumulated in the refrigerant tank while the pressure inside the refrigerant tank is in equilibrium with the pressure of the evaporator.Therefore, it is necessary to store a predetermined amount of refrigerant from the condenser into the refrigerant tank regardless of the temperature of the refrigerant. The excellent effect that can be obtained is obtained.

[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 an installation state of an air conditioner according to the present invention.

FIG. 3 shows a flowchart of a steady mode of operation of the air conditioner according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 outdoor unit 2 indoor unit 3 ventilation duct 4 intake duct 5 room 6 remote control 10 evaporator 11 ventilation fan 12 regenerator 13 burner 16 condenser 17 air cooling fan 18 refrigerant tank 20 absorber 21 dilute solution tank 25 passage 30 controller 31 communication Controller T1, T2, T3, T4 Sensor V1, V2, V3, V4, V5 Valve

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-247969 (JP, A) JP-A-1-134178 (JP, A) JP-A-56-155352 (JP, A) JP-A-6-155 235559 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00 306 F25B 15/00 301

Claims (1)

(57) [Claims] 1. A regenerator for generating a refrigerant vapor by heating a dilute solution in which water as a refrigerant is absorbed in an absorbent mainly composed of a lithium bromide aqueous solution, and air-cooling the refrigerant vapor generated by the regenerator. A condenser that condenses, an evaporator that is disposed in a duct through which the air to be air-conditioned flows, and is connected to the condenser via a pressure loss member such as a capillary, and an absorbing liquid that absorbs the refrigerant evaporated by the evaporator. And a refrigerant tank connected to the condenser via a valve. The refrigerant tank is used to balance the pressure inside the refrigerant tank with the pressure of the evaporator during the concentration of the solution. An air conditioner using an absorption refrigerator, wherein a passage portion directly connecting the evaporator and the evaporator is provided.