JP3313486B2 - 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 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 is connected to the steam line 1 from the regenerator 12.
9 is cooled by an air-cooling fan 17 and liquefied, the liquefied refrigerant is temporarily stored in a refrigerant tank 18, and the liquefied refrigerant is sent from the tank 18 to the evaporator 10. ing.

The refrigerant tank 18 stores a part of the refrigerant so as to adjust the concentration of the dilute solution supplied to the regenerator 12 by adjusting the total amount of the refrigerant circulating in the apparatus.

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.
From the dilute solution tank 21 to the regenerator 12.

V1, V2, V3, V4, V5a, V5b
Each of them is a regulating valve such as a solenoid valve. In particular, V3 has a check valve function for preventing a flow from the regenerator 10 side to the dilute solution tank 21 side.

[0019]

The air conditioner described above basically uses a pump 23 to supply a dilute solution from the dilute solution tank 21 to the regenerator 12, except that a pump 23 is used. A difference is created, and the refrigerant is sent out and circulated (cycled) by the pressure difference.

In particular, as a first condition for exhibiting a stable cooling capacity, it is necessary to reliably and stably send the refrigerant from the condenser 16 to the evaporator 10. Therefore, it is necessary to always maintain a stable pressure difference between the condenser 16 and the evaporator 10 and to suppress the rapid delivery of the refrigerant. Is provided with two valves 5a and 5b to prevent a pressure drop and a sudden delivery of the refrigerant from occurring during the delivery of the refrigerant. However, providing two valves in this portion complicates the apparatus and also complicates the operation of these valves.

Further, as a second condition for exhibiting a stable cooling capacity, it is necessary to appropriately adjust the concentration of the absorbing solution according to the situation such as the outside air temperature. For this purpose, the amount of the refrigerant liquefied by the condenser 16 to be sent to the cycle must be constantly adjusted. However, the liquefied refrigerant from the condenser 16 is always sent to the evaporator 10 through the refrigerant tank 18 for storing the refrigerant. In the conventional apparatus configured to perform the above operation, there is a disadvantage in adjusting the amount of refrigerant to be delivered.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make the destination of a liquefied refrigerant from a condenser one of a refrigerant tank and an evaporator as simple as possible. It is another object of the present invention to provide an air conditioner using an absorption refrigerator capable of adjusting the solution concentration by temporarily storing a refrigerant to be sent to a cycle in a refrigerant tank.

[0023]

According to the main aspect of the present invention, in order to achieve the above-mentioned object, the present invention is provided with an intake duct, a blow duct and one of the two ducts. Evaporation that is 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 fan is directly cooled, and is internally cooled by heat of vaporization. Vessels,
An absorber for storing an absorbing liquid that absorbs the vapor generated by the evaporator and flowing through the passage; a dilute solution tank that stores a dilute solution obtained by absorbing the vapor in the absorber; A regenerator for heating the dilute solution supplied from the dilute solution tank through a pump and a pipe to generate refrigerant vapor, and introducing the generated refrigerant vapor through a vapor pipe, cooling A condenser for sending the liquefied refrigerant to the evaporator via a first liquefied refrigerant pipe after liquefaction, and a condenser connected between the condenser and the dilute solution tank via a second liquefied refrigerant pipe. An air conditioner using an absorption refrigerator having a refrigerant tank for storing refrigerant, wherein the absorption refrigerator has a liquefied refrigerant outlet of the condenser and the second refrigerant.
A pressure loss means provided between the first liquefied refrigerant pipe and a branch portion for branching the liquefied refrigerant pipe from the first liquefied refrigerant pipe; A regulating valve provided to open and close the pipe line, wherein a destination of the liquefied refrigerant delivered from the condenser is the evaporator and the refrigerant tank by opening and closing control of the regulating valve. An air conditioner characterized by being able to be selected from any one of the following is provided.

According to another aspect of the present invention, there is provided the air conditioner according to the main aspect, wherein the pressure loss means is a capillary. .

[0025]

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 or the refrigerant tank according to the pressure difference between the condenser and the evaporator or according to the pressure difference between the condenser and the refrigerant tank. In the absorption refrigerator used in the air conditioner of the present invention, the pressure loss of the second liquefied refrigerant line leading from the condenser to the refrigerant tank is smaller than that of the first liquefied refrigerant line leading to the evaporator from the condenser. Thus, in a normal state, the liquefied refrigerant is sent to the refrigerant tank via the second liquefied refrigerant pipe. When the liquefied refrigerant is sent to the evaporator, the control valve (controller) performs a closing operation on a regulating valve provided in the second liquefied refrigerant pipe so as to perform the opening and closing operation by remote control. Close the liquefied refrigerant line. Thus, by controlling the opening and closing of this regulating valve, the destination of the liquefied refrigerant can be switched.

[0026]

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 almost 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 a blast temperature, and T3
Is a level sensor for detecting the liquid level of the regenerator, T4 is a temperature sensor for detecting the temperature of the liquefied refrigerant in the condenser, T5
Is a temperature sensor for detecting the outside air temperature.

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 signal from T2, T4, T5 and the level sensor T3 and a signal from the communication controller 31 are received, and the blower fan 11, the air cooling fan 17, the pump 23,
The fuel supply control valve 15 of the fuel supply pipe 14 and the respective regulating valves V1 to V1
Each operation of V5 is controlled according to the current driving situation.

Next, an operation flow of the cooling mode in the embodiment will be described with reference to FIG. Before starting operation, valve V
1, V3, V4, V5 are closed and only valve V2 is open. The regenerator 12 is empty.

[0031] When 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 vapor is generated in the regenerator 12, flows into the condenser 16, and the liquefied refrigerant temperature in the condenser 16 gradually increases. The CPU of the controller 30 determines whether or not the liquefied refrigerant temperature of the condenser 16 has reached a predetermined value from a signal from the sensor T4 (F-5). When the liquefied refrigerant temperature has reached the predetermined value, the valve V1 is opened. closing valve V2 (F-6), thereby rotating the cooling fan 17 driven by the blower fan 11 and the motor M ₁ (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-
10) 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 refrigerant tank 18 and the regenerator 1
2 in order to prevent corrosion. 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. .

Meanwhile, as one condition for smoothly shifting the cooling operation from the operation start to the steady operation and maintaining a steady steady operation state, the pressure difference between the evaporator 10 and the condenser 16 is always constant. 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.

As is apparent from FIG. 1, the liquefied refrigerant passage from the condenser 16 to the evaporator 10 in the embodiment of the present invention connects the condenser 16 and the evaporator 10 without passing through the refrigerant tank 18. A first liquefied refrigerant pipe 25 directly connected to the first liquefied refrigerant pipe 25, and a second liquefied refrigerant pipe branched from a branch point 27 in the middle of the first liquefied refrigerant pipe 25 and connected to the refrigerant tank 18 via an adjustment valve V5. And a pressure loss means 24 for maintaining a predetermined pressure difference before and after the liquefied refrigerant passage upstream of a branch point 27 between the first liquefied refrigerant pipe 25 and the second liquefied refrigerant pipe 26. Is provided. By providing the capillary, it is possible to prevent so-called flushing, in which the liquefied refrigerant rapidly flows into the evaporator at the time of starting the delivery of the liquefied refrigerant or restarting the cooling operation. , A predetermined pressure difference can be stably maintained.

The following table shows an example of the relationship between the temperature and the pressure of each part in the refrigeration absorber of the present invention.

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 As is clear from the above table, the pressure loss in the second liquefied refrigerant pipe 26 is smaller than the pressure loss in the first liquefied refrigerant pipe 25. Is also small. Accordingly, as described above, the regulating valve V5 is provided in the second liquefied refrigerant pipe 26, and the valve V5 is opened and closed by remote control from the controller 30, so that the refrigerant (liquefied refrigerant) liquefied in the condenser 16 is discharged to the second liquefied refrigerant pipe 26. Either delivery to the evaporator 10 via the first liquefied refrigerant line 25 or guide to the refrigerant tank through the second liquefied refrigerant line 26 can be selected. That is, when the valve V5 is closed, the liquefied refrigerant is sent out to the evaporator via the first liquefied refrigerant line 25, while when the valve V5 is opened, the liquefied refrigerant is transmitted through the second liquefied refrigerant line 26 to the refrigerant tank. It is led to 18.

As described above, the destination of the refrigerant condensed and liquefied by the condenser 16 can be freely switched, so that, for example, the solution (absorbing liquid) is concentrated during operation with the refrigerant tank 18 empty. Open valve V5 when needed,
The refrigerant is stored in the refrigerant tank 18 without being sent to the evaporator 10 and the absorber 20 until the concentration reaches a predetermined concentration. When the concentration of the solution reaches a predetermined concentration, the valve V5 is closed.

The pressure-loss means is not limited to the above-mentioned capillary, and any element having a pressure-loss function such as an aperture can be used suitably.

Further, in the above embodiment, an aqueous solution of lithium bromide was used as the absorbing solution, and water was used as the refrigerant, but other than these can also be suitably used.

[0043]

As described above, according to the present invention,
It has a smaller pressure loss than the first liquefied refrigerant line connecting the condenser and the evaporator, and opens and closes the second liquefied refrigerant line connecting the condenser and the refrigerant tank by remote control from the controller. An air conditioner using a refrigeration absorber that can reliably switch the destination of liquefied refrigerant from a condenser to a refrigerant tank or from a condenser to an evaporator by applying simple means that only has a regulating valve. Can be provided.

[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 an explanatory diagram showing an installation state of an air conditioner proposed in the prior application.

FIG. 4 is a block diagram showing a main configuration of an air conditioner proposed in the prior application.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 outdoor unit 2 indoor unit 3 blower duct 4 intake duct 5 room 6 remote controller 10 evaporator 11 blower fan 12 regenerator 13 burner 14 fuel supply pipe 15 fuel supply control valve 16 condenser 17 air cooling fan 18 refrigerant tank 19 steam pipe Path 20 Absorber 21 Dilute solution tank 22 Heat exchanger 23 Pump 24 Pressure drop means 25 First liquefied refrigerant line 26 Second liquefied refrigerant line 30 Controller 31 Communication controller T1, T2, T4, T5 Temperature sensor T3 Level sensor V1 , V2, V3, V4, V5 control valve M _1, M ₂ motor

Continuation of the front page (56) References JP-A-56-155352 (JP, A) JP-A-58-78062 (JP, A) JP-A-62-200149 (JP, A) JP-A-7-91766 (JP) , A) Fully open sho 59-128076 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00 301 F25B 15/00 306

Claims (2)

(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 that is installed at a boundary between the intake duct and the air duct and that is internally cooled by heat of vaporization, and for storing an absorbing liquid that is generated by the evaporator and absorbs steam flowing through a passage. An absorber, a dilute solution tank for storing a dilute solution obtained by absorbing the vapor in the absorber, and a refrigerant that heats the dilute solution supplied from the dilute solution tank via a pump and a pipe line. A regenerator for generating vapor, and a refrigerant for introducing the generated refrigerant vapor through a vapor line, cooling and liquefying the liquid refrigerant, and then sending the liquefied refrigerant to the evaporator through a first liquefied refrigerant line. An air conditioner using an absorption refrigerator having a condenser and a refrigerant tank for storing refrigerant connected through a second liquefied refrigerant pipe between the condenser and the dilute solution tank, A pressure-loss means provided between the liquefied refrigerant outlet of the condenser and a branch for branching the second liquefied refrigerant pipe from the first liquefied refrigerant pipe; A regulating valve that is provided on the side of the second liquefied refrigerant pipe on the side where the pressure loss is low and that can open and close the pipe; further comprising: a liquefied refrigerant discharged from the condenser therein. An air conditioner, wherein the destination of the air conditioner can be selected to one of the evaporator and the refrigerant tank by opening and closing control of the regulating valve. 2. The air conditioner according to claim 1, wherein the pressure loss means is a capillary.