JP3124661B2 - 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, 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 having a cooling mode in which the evaporator is positioned in a passage through which room air to be air-conditioned passes, and the room air is directly contacted with the outside of the evaporator to perform cooling with a pressure difference. (Japanese Patent Application No. 5-2351 / 1993).

FIG. 3 shows an installation state of the air conditioner proposed in the above-mentioned application, and FIG. 4 shows a main configuration of a modified example of the air conditioner proposed in the application.

The proposed air conditioner comprises an outdoor unit 1 and an indoor unit 2 as shown in FIG. 3, 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 connected by a blow duct 3 for cool air and an intake duct 4 for indoor air. 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 the automatic operation, setting the room temperature, adjusting the amount of cool air to be blown out, and the like.

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 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 generating refrigerant vapor by heating the absorption liquid (dilute solution) whose concentration has been reduced by absorbing the refrigerant by the burner 13 and concentrating the concentration of the absorption 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 apparatus and for storing a part of the refrigerant for adjusting the concentration of the dilute solution supplied to the regenerator 12. And is connected to the condenser 16.

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 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 relatively low-concentration low-temperature absorbing solution (dilute solution) flowing from the dilute solution tank 21 to the regenerator 12 and a relatively high-concentration high-temperature absorbing solution flowing from the regenerator 12 to the absorber 20. A heat exchanger that exchanges heat between
23 is an absorbing solution (dilute solution) whose concentration has been reduced by absorbing the refrigerant.
Pumping out of the dilute solution tank 21 to the regenerator 12,
Reference numeral 24 denotes a capillary provided between the upstream side of the evaporator 10 and the downstream side of the condenser 16 or a pressure loss means corresponding thereto.

Each of V1, V2, V3, V4, and V5 is an automatic regulating valve such as a solenoid valve. In particular, V4 also has a check valve function that does not flow from the dilute solution tank 21 to the refrigerant tank 18 side. ing.

The air conditioner described above basically creates a pressure difference between each element, except that a pump 23 is used to supply the dilute solution from the dilute solution tank 21 to the regenerator 12. The refrigerant is sent out and circulated by the difference.

[0020]

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 outside air temperature, etc. It is required to continue the appropriate smooth and stable operation. Stable circulation of the refrigerant according to the situation in the absorption refrigeration mechanism provided in the outdoor unit is one means for achieving the demand. A pump is used only for supplying the dilute solution to the regenerator, and the circulation of the refrigerant itself is performed by the pressure difference of each part in the apparatus. In order to maintain a stable cooling capacity, it is necessary to always maintain a constant pressure in the condenser so as to maintain a predetermined pressure difference with respect to an evaporator having a preset pressure. In other words, since the pressure of the condenser depends on the temperature of the condenser (more precisely, the temperature of the liquefied refrigerant in the condenser), it is necessary to always keep the temperature of the liquefied refrigerant in the condenser at a predetermined temperature.

The present invention has been made in view of the above circumstances, and an object of the present invention is to always maintain the temperature of a liquefied refrigerant in a condenser at a predetermined temperature so that the refrigerant is delivered from the condenser to an evaporator. It is an object of the present invention to provide an air conditioner using an absorption refrigerator capable of securing a predetermined pressure difference for performing cooling and maintaining a stable cooling capacity.

[0022]

According to the main aspect of the present invention, in order to achieve the above object, the present invention is provided with an intake duct, a blow duct and one of the two ducts. An evaporator installed at the boundary between the intake duct and the air duct, so that the air circulated between the room to be air-conditioned and the air conditioner via the air blowing fan is directly cooled, An absorber for containing the absorbing liquid for absorbing the generated vapor, and a regenerator for generating a refrigerant vapor by heating a dilute solution obtained by absorbing the vapor in the absorber. An air conditioner using an absorption refrigerator including a condenser for sending out a liquefied refrigerant to the evaporator after cooling and liquefying the generated refrigerant vapor, wherein a means for detecting an outside air temperature, Heating in regenerator Means for adjusting the power stepwise or steplessly within a predetermined range; means for detecting the heating capacity; and a motor capable of adjusting the cooling capacity for the condenser stepwise or steplessly within a predetermined range. An air-cooling fan comprising: a means for detecting the number of rotations of the motor of the air-cooling fan; and the air-cooling fan according to a plurality of preset combination patterns for each change in the heating capacity and the outside air temperature in the regenerator. Storage means for storing a plurality of types of appropriate rotational speed data for the motor, and inputting the outside air temperature and the heating capacity as a feedforward signal, and converting the external air temperature and the heating capacity into appropriate rotational speed data according to the heating capacity. Control means for controlling a motor of the air-cooling fan based on the air conditioner.

[0023]

The high-temperature and high-pressure vapor refrigerant sent from the regenerator is guided to a condenser, where it is cooled and liquefied. The liquefied refrigerant is delivered to the evaporator according to the pressure difference between the condenser and the evaporator having a preset pressure. Since the pressure in the condenser depends on the temperature of the liquefied refrigerant in the condenser, an air-cooling fan for cooling the condenser is used to stably deliver the liquefied refrigerant so that the temperature of the liquefied refrigerant always keeps a predetermined value. The performance (motor speed) is controlled.

The rotation speed control of the air-cooling fan motor is performed by controlling a plurality of appropriate rotation speeds for the air-cooling fan motor according to a plurality of predetermined combination patterns of the outside air temperature and the heating capacity of the regenerator. The feed-forward control is achieved by storing data in a storage unit as a table and using the combination information of the actually detected outside air temperature and the determined heating capacity as an address for reading the table.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of the present invention will now be described with reference to the accompanying drawings (FIGS. 1 and 2). FIG. 1 shows a main part of an embodiment of an air conditioner using a single-effect absorption chiller embodying the present invention. The installation state of the air conditioner according to the present invention is as shown in the example shown in FIG.

The configuration of the embodiment of the present invention shown in FIG. 1 is substantially the same as that of the above-described embodiment shown in FIG. 4 except for the control system, and the units having the same functions are denoted by the same reference numerals. Description is omitted. Here, a control circuit necessary for operation control of the apparatus and operation of the apparatus will be described.

In FIG. 1, T1 is a temperature sensor for detecting a room temperature provided in an intake duct located on the upstream side of the evaporator 10, T2 is a temperature sensor for detecting an air blowing temperature, and T3.
Is a level sensor for detecting the liquid level of the regenerator, T4 is a temperature sensor for detecting the condenser temperature, T5 is a temperature sensor for detecting the outside air temperature, and T6 is a flame sensor for the burner 13.

In the control circuit, in addition to the above sensors, C
A controller 30 including a PU, a memory, and a drive circuit;
There is provided a communication controller 31 that receives a setting signal from the remote controller 6 (see FIG. 3) at the receiving unit 2a of the indoor unit 2 and receives a signal from the receiving unit 2a. The controller 30 includes a temperature sensor T1, Each information signal from T2, T4, T5 and the level sensor T3, the information signal from the communication controller 31, and the combustion detector (flame sensor) T6 of the burner 13
And the air supply fan 11, the air cooling fan 17, the pump 23, and the fuel supply control valve 1 of the fuel supply pipe 14.
5. The operation of each of the valves V1 to V5 is controlled in accordance with the current operating condition.

Next, the operation flow of the cooling mode in the embodiment will be described with reference to FIG. Before starting operation, valve V
1, V3, V5 are closed and valve V2 is open. The regenerator 12 is empty.

[0030] Upon turning on the operation button of the remote control device 6, 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 supplied to the regenerator 12 ( F-2). Other valves remain as they are. At this time, the CPU of the controller 30 checks the signal from the sensor T3 to determine whether the liquid level of the regenerator 12 has reached a prescribed level (F-3).

When the liquid level has reached a specified level,
The fuel supply control valve 15 is opened, fuel gas is supplied from the fuel supply pipe 14, and the burner 13 is ignited (F-4). continue,
Refrigerant 12 generates refrigerant vapor, which flows to condenser 16, and the temperature of condenser 16 gradually increases. The CPU of the controller 30 determines whether or not the temperature of the condenser 16 has reached a predetermined value from a signal from the sensor T4 (F-5). When the temperature has reached the predetermined value, the valve V1 is opened, while the valve V2 is opened. Is closed (F-6), and the blowing fan 11 and the air-cooling fan 17 are rotated (F-7).

As a result, in the condenser 16, the refrigerant vapor sent from the regenerator 12 is liquefied, and the liquefied refrigerant flows into the evaporator 10 due to the pressure difference between the condenser 16 and the evaporator 10. The refrigerant evaporates (vaporizes) inside the evaporator 10.
Then, 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 outer surface of the evaporator 10. 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.
A cooling operation for cooling the room 5 is started (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 been reduced by absorbing the refrigerant once enters the dilute solution tank 21 and then passes through the valve V3 by the pump 23 and the high-concentration high-temperature absorbent which is sent out of the regenerator 12 by the heat exchanger 22 and heat. It is exchanged and sent to the regenerator 12 again. This is the steady mode of the cooling operation, during which the valve V5 repeats opening and closing as necessary.

When stopping the operation, the remote controller 6
Is turned off (F-9). Thereby, the blower fan 11 and the air cooling fan 17 stop (F-1).
0) During that time, the valve V2 and the valve V4 are opened so that 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 absorption liquid causes the refrigerant tank 18 and the regenerator 12
This is for preventing corrosion of the solution and diluting the solution so that the concentrated solution of the absorbing solution does not crystallize. Thereafter, with a slight delay, the pump 23 is stopped (F-11), all the liquid flows in the entire apparatus are stopped, only the valve V2 is opened, and the remaining valves are all closed.

Incidentally, as one condition for smoothly shifting the cooling operation from the operation start to the steady operation, and thereafter maintaining a steady steady operation state, the pressure difference between the evaporator 10 and the condenser 16 is always determined. There is a problem that the value is kept at a predetermined value. That is, the circulation of the refrigerant in the air conditioner of the present invention is performed by the pressure difference between the respective elements,
Delivery of the liquefied refrigerant from 6 to the evaporator 10 is also made by the pressure difference between the two. Since the internal pressure of the evaporator 10 is set to a predetermined value (10 to 20 Torr) in advance, it is necessary to maintain the internal pressure of the condenser 16 at a predetermined value. Stable delivery of the liquefied refrigerant is always achieved reliably. As a result, stable cooling capacity is maintained.

Here, the internal pressure of the condenser 16 depends on the temperature of the condenser (more precisely, the temperature of the liquefied refrigerant at the liquefied refrigerant outlet of the condenser). Therefore, maintaining the temperature of the condenser 16 at a predetermined value will maintain the internal pressure of the condenser 16 at a predetermined value.

The temperature of the condenser 16 changes due to a change in the amount of generated steam refrigerant based on a change in the heating capacity (heating amount) in the regenerator 12 and a change in the outside air temperature. In this case, in order to maintain the liquefied refrigerant temperature at the liquefied refrigerant outlet of the condenser 16 at a predetermined value, the capacity (the number of revolutions) of the air cooling fan 17 used for cooling the condenser 16 depends on the temperature change of the liquefied refrigerant. It needs to be adjusted accordingly.

For this purpose, a method (feedback control) of detecting the liquefied refrigerant temperature at the liquefied refrigerant outlet of the condenser 16 and controlling the number of rotations of the air-cooling fan based on the detected temperature, and a method of controlling the outside air temperature and the regenerator 12 A control method (feedforward control) in which a plurality of types of combination patterns relating to a change in the heating capacity are stored as a preset table, and the actually detected outside air temperature and the heating capacity are used as addresses for reading the table. You could think so. Since the former has been filed as a separate application by the same applicant and the same inventor, the latter is taken up in the present application and will be described in detail below.

As is clear from FIG. 1, the controller 3
A temperature sensor T5 for detecting the outside air temperature is connected to 0, and a flame sensor T6 for detecting the heating capacity (heating amount, that is, the degree of combustion of the burner) in the regenerator 12 is connected as described above. The information relating to the outside air temperature and the combustion detected respectively by them is always inputted to the controller 30. Further, a controller 15 a of a fuel supply control valve 15 provided in the fuel gas supply pipe 14 is also connected to the controller 30 in order to control the heating capacity of the burner 13.

On the other hand, as shown in the control block diagram of FIG. 3, a memory 32 as a storage unit provided in the controller 30 stores a plurality of types of presets for each change in the heating capacity and the outside air temperature. more aptitude rotational speed data of the motor M ₁ for the cooling fan 17 corresponding respectively to the combination patterns are stored as a table.

The temperature information t relating to the actual outside air temperature and the information Q relating to the actual combustion detected by the temperature sensor T5 and the flame sensor T6, respectively, are transmitted to the controller 30.
In the stage where the CPU 33 provided in the
3 reads the suitability rotational speed data N of the motor M ₁ for the cooling fan 17 commensurate with the amount of information of both the time that the information t and Q as an address from the memory 32.
Then, the read output control signal S1 from the CPU33 to the motor drive circuit 34 based on the suitability rotational speed data N, the motor drive signal S2 to the motor M ₁ from the motor driving circuit 34 rotates at a proper rotational speed There is output to the motor M _1.

As described above, by maintaining the temperature of the liquefied refrigerant in the condenser 16 at a predetermined temperature, the pressure in the condenser 16 is maintained at a constant pressure, and the liquefied refrigerant from the condenser 16 to the evaporator 10 is stabilized. The air-conditioning apparatus of the present invention can exhibit a stable cooling capacity.

In the above embodiment, an aqueous solution of lithium bromide was used as the absorbing solution, and water was used as the cooling medium.

[0044]

As described above, according to the present invention,
By controlling the rotation speed of the motor for the air cooling fan used for cooling the condenser in accordance with the outside air temperature and the heating capacity of the regenerator, the temperature of the liquefied refrigerant in the condenser was kept at a predetermined value. In addition, it is possible to provide an air conditioner in which stable delivery of the liquefied refrigerant from the condenser to the evaporator is achieved and stable cooling ability can be exhibited.

[Brief description of the drawings]

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

FIG. 2 is a flowchart of a cooling mode in the air conditioner according to the present invention.

FIG. 3 is a control block diagram of the air conditioner according to the present invention.

FIG. 4 is an explanatory diagram showing an installation state of an air conditioner proposed in the prior application.

FIG. 5 is a block diagram showing a main configuration of a modification of the air conditioner proposed in the prior application.

[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 15a control unit 16 condenser 17 air cooling fan 18 refrigerant tank Reference Signs List 20 absorber 21 dilute solution tank 30 controller 31 communication controller 32 memory 33 CPU 34 motor drive circuit T1, T2, T4, T5 temperature sensor T3 level sensor T6 flame sensor V1, V2, V3, V4, V5 valve t temperature information Q Combustion information N Appropriate rotation speed data S1 Control signal S2 Motor drive signal

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-260268 (JP, A) JP-A-49-1224659 (JP, A) JP-A-5-60414 (JP, A) 92063 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00 306

Claims (1)

(57) [Claims] The air circulated between a room to be air-conditioned and an air conditioner is directly cooled via an air intake duct, a ventilation duct, and a ventilation fan provided inside one of the two ducts. An evaporator installed at the boundary between the intake duct and the blower duct, an absorber for containing the absorbing liquid for absorbing the vapor generated by the evaporator, and vapor in the absorber. A regenerator for heating the diluted solution obtained by absorption to generate refrigerant vapor, and a condenser for sending out the liquefied refrigerant to the evaporator after cooling and liquefying the generated refrigerant vapor. An air conditioner using an absorption refrigerator including: a means for detecting an outside air temperature; a means for adjusting a heating capacity of the regenerator stepwise or steplessly within a predetermined range; and Detect Means, a cooling fan having a motor capable of adjusting the cooling capacity of the condenser stepwise or steplessly within a predetermined range, means for detecting a motor rotation speed of the air cooling fan, Storage means for storing a plurality of types of suitable rotation speed data for the motor of the air-cooling fan according to a plurality of preset combination patterns for each change in the heating capacity and the outside air temperature, respectively, An air conditioner comprising: a control unit that inputs a heating capacity as a feedforward signal and controls a motor of the air-cooling fan based on appropriate rotation speed data corresponding to the outside air temperature and the heating capacity.