JP3229464B2 - 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).

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. 6 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. 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. 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 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 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 a 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 a part of the refrigerant is stored in a refrigerant tank in order to adjust the average concentration of the circulating solution. Store at 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, V5 are all control valves such as solenoid valves. In particular, V4 is a valve having a check function that does not flow from the dilute solution tank 21 side to the refrigerant tank 18 side. .

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.

[0019]

In the above air conditioner, the regenerator 12 is heated by the burner 13 to generate a refrigerant to be sent to the absorber 20 and a concentrated solution to be sent to the condenser 16. For example, if foreign matter (for example, crystal of the solution) is clogged in the pipe from the regenerator 12 to the absorber 20 or the pipe from the regenerator 12 to the condenser 16, the pipe line is blocked, and the refrigerant or the concentrated solution cannot be delivered.

In this case, although the dilute solution is fed into the regenerator 12 by the pump 23, the refrigerant and the concentrated solution are not sent out, so that the regenerator 12 overflows with the solution. As a result, the solution also flows into the condenser 16. If the cooling operation is continued in this state, not only the desired cooling cannot be performed but also the air conditioner may be damaged.

The present invention has been made in view of the above points, and when there is an abnormality in the piping and the delivery from the regenerator is not performed smoothly, the safety of the emergency stop of the air conditioner is promptly stopped. An object is to provide a high air conditioner.

[0022]

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 that absorbs, a regenerator that heats the dilute absorbent that has absorbed the refrigerant vapor to generate refrigerant vapor and a concentrated absorbent, a condenser that condenses the refrigerant vapor generated by the regenerator, and a circulating refrigerant A refrigerant tank for storing a refrigerant that is not circulated in order to adjust the total amount of the refrigerant tank, and refrigerant amount detecting means for detecting the amount of refrigerant in the refrigerant tank.The evaporator directly cools indoor air to be air-conditioned by the evaporator. In an air conditioner using an absorption refrigerator that blows cooled air into a room through a duct to perform cooling, a liquid surface level detection unit that detects a liquid surface level of the diluted absorption liquid in the regenerator, By liquid level detection means The heating in the regenerator is started when the detected liquid level of the diluted absorption liquid reaches a predetermined upper limit position, and then the operation is stopped when the liquid level does not fall below the predetermined upper limit position within a predetermined time. The air conditioner was constituted by the emergency stop means.

[0023]

According to the present invention, the emergency stop means monitors the liquid level of the dilute absorbing solution in the regenerator detected by the liquid level detecting means and waits for a predetermined time after the regenerator starts heating. If the liquid level does not drop below the predetermined position, the operation of the air conditioner is stopped.

[0024]

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.

Since the configuration of the air conditioner according to the present invention is the same as that shown in FIG. 5, the description thereof will be omitted, but the electric circuit necessary for controlling the device will be described.

T1 is a sensor for detecting the indoor 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, and T4 is a sensor for detecting the condenser temperature. T5 is a sensor for detecting the amount of refrigerant in the refrigerant tank. The sensor T3 comprises an upper limit position sensor 121 and a lower limit position sensor 122 shown in FIG.

A controller 30 comprising a CPU, a memory and a drive circuit, and a communication controller which receives a setting signal from the remote controller 6 (see FIG. 6) at the receiving section 2a of the indoor unit 2 and receives a signal from the receiving section 2a. 31 are provided, and the controller 30 includes sensors T1, T2, T3, T4, and T5.
And the signals from the communication controller 31 to control the operations of the blower fan 11, the air cooling fan 17, the pump 23, and the fuel supply control valve 15 of the fuel supply pipe 14.

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

Before starting operation, the valves V1, V3, V5 are closed and the valves V2, 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, the CP of the controller 30
U determines whether or not the liquid level of the regenerator 12 has reached a prescribed level by watching the signal from the sensor T3 in order to prevent idling (F-3). When the liquid level reaches a predetermined level (the level of the upper limit position sensor 121 in FIG. 3 described later), 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. The CPU of the controller 30 determines whether or not the temperature of the condenser 16 has reached a predetermined value based on a signal from the sensor T4 (F-5), and when the temperature has reached the predetermined value, rotates the air-cooling fan 17 (F-5). 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 of the controller 30 looks at the signal from the sensor T5 and determines whether or not the refrigerant in the refrigerant tank 18 has reached a predetermined amount (F−
7) When the predetermined value is reached, 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 through 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 of the refrigerant. Cool the incoming air. The cooled air passes through the air duct 3 and the indoor unit 2
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 into vapor 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.

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: 30 to 90-Intake duct 4: 26 (room temperature)-Blast duct 3: 13 to 20-Dilute solution: 35 -40 concentration: 61% concentrated solution: 90 concentration: 64.8% When the start button of the remote controller 6 is turned off (F-
11) After the stop processing is performed (F-12), the processing ends. As the stop processing, first, the burner 13 is extinguished, and the valve V2,
Open V4 and close valve V1. 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 absorbing liquid in the regenerator 12 all flow into the dilute solution tank 21. This is because the refrigerant tank 18 and the regenerator 1
2 to prevent corrosion, and dilute the concentrated solution to prevent crystallization.

Next, the emergency stop processing according to the present invention will be described.

FIG. 3 is a sectional view of the regenerator 12.

The dilute solution 125 is supplied from the dilute solution tank 21 to the regenerator 12 via the dilute solution supply port 120 by the pump 23. The liquid level of the dilute solution 125 in the regenerator 12 is determined by the upper limit position sensor 121 and the lower limit position sensor 12.
2 detected. Each of the sensors 121 and 122 outputs a predetermined signal when the liquid level of the dilute solution 125 reaches the height position at which the sensors 121 and 122 are attached.

At the start of operation of the air conditioner, the burner 13 is ignited after the dilute solution 125 in the regenerator 12 reaches the position of the upper limit position sensor 121 in order to prevent the boil-off. When the burner 13 is ignited and the regenerator 12 is heated, the dilute solution 125 boils and jumps at the liquid level. As a result, the refrigerant in the dilute solution 125 evaporates and is sent to the condenser 16 via the refrigerant outlet 124.
On the other hand, the concentrated solution whose concentration has increased due to evaporation of the refrigerant jumps up on the liquid surface and is sent out to the absorber 20 through the concentrated solution outlet 123. During the cooling operation of the air conditioner, the liquid level of the regenerator 12 is at the upper limit position, that is, the upper limit position sensor 121.
And the lower limit position, that is, the lower limit position sensor 122.

FIG. 4 is a flowchart of the emergency stop process according to the present invention.

[0043] When the ignition to the burner 13 at step (F-4) of FIG. 2, a dilute solution 125 boiling, liquid level of dilute solution 125 after a predetermined time t ₀ has elapsed at the time of normal in the regenerator 12 is the upper limit position Lower than. However, if the pipe from the regenerator 12 is blocked, the predetermined time t
_The liquid level does not drop even after ₀ has elapsed.

Therefore, in the present processing, the operation of the air conditioner is urgently stopped when the liquid level does not fall below the upper limit position even after a predetermined time t ₀ has elapsed after the burner 13 is ignited. Since the predetermined time t ₀ depends on the heat of the burner 13, the heat of the burner 13 and the predetermined time t ₀ are stored in the memory of the controller 30 in advance.

This process proceeds in parallel with the process shown in FIG. 2 after the burner 13 is ignited in step (F-4) in FIG.

First, a predetermined time t ₀ according to the present heating power of the burner 13 is read from the memory of the controller 30 (S-1). Next, it is determined whether or not the liquid level of the regenerator 12 has dropped below the upper limit position (S-2). If the liquid level has fallen below the upper limit position, it is normal and the process ends.

Meanwhile, the step (S-2) in the regenerator 12 the liquid surface level unless lower than the upper limit position, the elapsed time from the ignition of the burner 13 it is determined whether the past predetermined time t ₀ (S -3). If not, the process returns to step (S-2) to continue the process.

If the elapsed time from the ignition of the burner 13 has exceeded the predetermined time t ₀ in step (S-3), the process is terminated after performing the stop processing (S-4). This stop processing is performed as shown in FIG.
Since this step is the same as step (F-12), description thereof will be omitted.

In this embodiment, an aqueous solution of lithium bromide is used as the absorbing solution and water is used as the refrigerant, but the present invention is not limited to this.

[0050]

As described above, according to the present invention,
If there is an abnormality in the piping system from the regenerator to the condenser or from the regenerator to the absorber or the dilute solution tank and the pipe line is blocked, and the output from the regenerator cannot be performed smoothly, the air conditioner Operation can be stopped urgently.

As a result, it is possible to provide a highly safe air conditioner without continuing operation when an abnormality occurs.

[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 cross-sectional view of the regenerator 12.

FIG. 4 is a flowchart of an emergency stop process according to the present invention.

FIG. 5 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. 6 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 120 dilute solution supply port 121 upper limit position sensor 122 lower limit position sensor 123 concentrated solution outlet 124 refrigerant outlet 125 Dilute solution 13 Burner 16 Condenser 17 Air cooling fan 18 Refrigerant tank 20 Absorber 21 Dilute solution tank 30 Controller 31 Communication controller T1, T2, T3, T4, T5 Sensor V1, V2, V3, V4, V5 Valve

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-231360 (JP, A) JP-A-53-6948 (JP, A) JP-A-2-136658 (JP, A) (58) Investigation Field (Int.Cl. ⁷ , DB name) F25B 15/00 306

Claims (2)

(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 diluted absorbing liquid for absorbing the refrigerant vapor. A regenerator that generates a refrigerant vapor and a concentrated absorption liquid, a condenser that condenses the refrigerant vapor generated by the regenerator, a refrigerant tank that stores a refrigerant that is not circulated to adjust the total amount of circulating refrigerant, Means for detecting the amount of refrigerant in the refrigerant tank, wherein the evaporator directly cools the air in the room to be air-conditioned and sends the cooled air into the room via a duct to perform cooling. In an air conditioner using an absorption refrigerator, a liquid level detecting means for detecting a liquid level of the rare absorbing liquid in the regenerator; and a liquid level of the rare absorbing liquid detected by the liquid level detecting means. When you reach the predetermined upper limit position The heating was started in the regenerator, then the air conditioning system, characterized in that a and emergency stop means for stopping the operation when the liquid level within the predetermined time has not fall below the predetermined upper limit position. 2. The emergency stop means includes storage means for storing the predetermined time for each heating amount in the regenerator, and reads out the predetermined time from the storage means in accordance with the current heating amount in the regenerator. The air conditioner according to claim 1, wherein the operation is stopped when the liquid level does not fall below the predetermined upper limit position within the read-out predetermined time after starting heating in the regenerator.