JPH07103597A - Air-conditioning equipment using absorptive refrigerating machine - Google Patents

Abstract

PURPOSE:To make an absorbent have the maximum allowable concentration at the outdoor air temperature at the time point when a user starts an absorptive refrigerating machine, obviate an operation for concentrating the absorbent and thereby enable quick attainment of a maximum cooling capacity suitable for the outdoor air temperature at the time of the start. CONSTITUTION:A temperature sensor T5 which detects an outdoor air temperature constantly so that an absorbent in an absorber 20 may have the maximum allowable concentration at the outdoor air temperature at the time point when an absorption type refrigerating machine is started for starting a cooling operation, and a level sensor T6 which detects a liquid level in a refrigerant tank 18, are provided. A specific liquid level corresponding to the outdoor air temperature at the time of the start is set by a controller 30 and the liquid level in the refrigerant tank 18 is regulated in accordance with the specific level.

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 refrigerating machine for general houses and small buildings.

[0002]

2. Description of the Related Art At present, an air conditioner using an absorption chiller is mainly used for industrial or commercial facilities such as a building or a large store.

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 for evaporation. The cooling heat medium (usually water) that circulates between the fan coil unit provided in the room to be cooled and the refrigerator is cooled by the latent heat of vaporization at that time. On the other hand, the evaporated refrigerant vapor is operated in a cycle in which a water-cooled absorber absorbs the concentrated solution (absorption liquid) and returns it to the regenerator.

In an air conditioner using this type of absorption refrigerator, the temperature of the cold heat medium circulated in the indoor fan coil unit is cooled to around 7 ° C. in the evaporator, and the cold heat medium is circulated in the indoor fan coil. It is circulated to cool the indoor air and return it to the evaporator at around 12 ° C. When using an aqueous lithium bromide solution as the absorbing liquid, it is necessary to maintain the temperature of the absorbing liquid in the absorber at around 40 ° C. To maintain this temperature, a cooling tower is installed on the rooftop or the like, and the water cooling circuit is installed. The method of cooling is adopted.

However, the conventional air conditioner using the absorption type refrigerating machine adopting such a water cooling system has the following problems.

(1) Since the temperature of the absorber is controlled by a water cooling system, the equipment becomes large and piping is required. Therefore, a lot of construction cost is required, which is a problem for general houses and small buildings. Not suitable for cooling.

(2) Since it is necessary to connect the fan coil unit and the refrigerator in the room to be cooled by the pipe for circulating the heating / cooling medium, the construction cost and equipment cost are high. The same applies to an ammonia absorption refrigerator that uses ammonia water as the absorbing liquid and the refrigerant.

Therefore, the present inventors cool the condenser and the absorber by an air cooling method instead of the water cooling method during the cooling operation, and the refrigerant is sent 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 the room air to be air-conditioned passes and the room air is cooled by directly contacting the room air with the outside of the evaporator. (Japanese Patent Application No. 5-22351).

FIG. 3 shows the installation state of the air conditioner proposed in the above application, and FIG. 4 shows the main configuration of the air conditioner proposed in the same application.

As shown in FIG. 3, the proposed air conditioner comprises an outdoor unit 1 and an indoor unit 2, and the outdoor unit 1 has the structure as shown in FIG. The indoor unit 2 has only an outlet for cool air and an inlet for indoor air, and is disposed inside the chamber 5. The outdoor unit 1 and the indoor unit 2 are connected by a blower duct 3 for cold air and an intake duct 4 for indoor air. A blower fan 11 is provided at a predetermined place in the blower duct 3 or the intake duct 4. Reference numeral 6 denotes a remote controller for starting or stopping the operation of the air conditioner, setting or canceling automatic operation, setting the room temperature, adjusting the amount of cold air blown out, and the like.

The inside of the outdoor unit 1 has a structure as shown in FIG. 4, in which an aqueous lithium bromide solution is used as the absorbing liquid and water is used as the refrigerant.

The evaporator 10 is installed at a position where the blower duct 3 and the intake duct 4 are connected to each other. The inside of the evaporator 10 evaporates the refrigerant due to the depressurization action, and the latent heat of vaporization (vaporization heat) acts to cool it from the inside. I am supposed to receive it.

The regenerator 12 has a function of generating a refrigerant vapor by absorbing the refrigerant and heating the absorbent (dilute solution) having a low concentration by the burner 13 and concentrating the concentration of the absorbent. Fuel supply pipe 1 to burner 13
4, fuel gas is supplied, and the degree of combustion is adjusted by the fuel supply control valve 15.

The condenser 16 cools the refrigerant vapor sent from the regenerator 12 by the air-cooling fan 17 and liquefies it, temporarily stores the liquefied refrigerant in the refrigerant tank 18, and the liquefied refrigerant from the tank 18 is evaporated. It has a function of sending to.

The refrigerant tank 18 stores a part of the refrigerant in order to adjust the total amount of the refrigerant circulating in the apparatus and the concentration of the dilute solution supplied to the regenerator 12.

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 cooled by the same air cooling fan 17 as the condenser 16. The absorbing liquid whose concentration has been reduced by absorbing the refrigerant is temporarily stored in the dilute solution tank 21.

Reference numeral 22 denotes a low-concentration low-concentration absorption liquid (dilute solution) from the dilute solution tank 21 to the regenerator 12 and a high-concentration high-temperature absorption liquid from the regenerator 12 to the absorber 20. A heat exchanger that exchanges heat between
23 is an absorbing liquid (dilute solution) whose concentration is reduced by absorbing the refrigerant
Is a pump for delivering the water from the dilute solution tank 21 to the regenerator 12.

All of V1, V2, V3, V4, and V5 are adjusting valves such as solenoid valves, and in particular, the valve V4 is a check valve that blocks the flow of the dilute solution from the dilute solution tank 21 side to the refrigerant tank 18 side. It has a valve function.

[0019]

Since the absorption type refrigerator used in the above air conditioner has a larger cooling capacity as the concentration of the absorbing liquid for absorbing the refrigerant increases when the outside air temperature is high, the absorption type refrigerating device has a large cooling capacity. For example, the absorption liquid concentration operation is performed.
However, since the maximum cooling capacity cannot be obtained during this concentration operation, optimal air conditioning cannot be performed when the air conditioning load in the room that requires air conditioning is large, and it takes time to reach the set temperature.

The present invention has been made in view of the above circumstances, and an object thereof is to determine the concentration at which the absorbing liquid can exert its maximum cooling capacity in accordance with the outside air temperature when the cooling operation is interrupted or stopped. It is an object of the present invention to provide an air conditioner using an absorption refrigerator, which has a control mechanism for either concentrating or diluting the absorption liquid so that the standby mode can be maintained at all times.

[0021]

In order to achieve the above-mentioned object, the present invention is, according to the main aspect of the present invention, provided inside an intake duct, a ventilation duct, or both of these ducts. It is installed at the boundary between the intake duct and the blower duct so that the air circulated between the air-conditioned room and the air conditioner via the blower fan is directly cooled, and is internally cooled by evaporative heat. An evaporator, an absorber for containing an absorbing liquid that absorbs vapor generated in the evaporator, a dilute solution tank for storing a dilute solution obtained by absorbing vapor in the absorber, A regenerator for heating the dilute solution supplied from the dilute solution tank via the pump to generate a refrigerant vapor, and for delivering the liquefied refrigerant to the evaporator after cooling and liquefying the generated refrigerant vapor. of An air conditioner using an absorption refrigerating machine having a compressor and a refrigerant tank for storing a refrigerant provided via a pipe between the condenser and the dilute solution tank, the interruption of the cooling operation. Alternatively, at the time of stoppage, control for performing either concentration or dilution of the absorption liquid so that the absorption liquid can always maintain a standby mode that maintains a concentration capable of outputting maximum cooling capacity according to the outside air temperature. An air conditioner provided with a mechanism is provided.

According to another aspect of the present invention, the control mechanism in the main aspect described above includes a remote control operation switch for selecting the standby mode, and a temperature sensor for detecting an outside air temperature and outputting a detection result. A means for detecting and storing the liquid level in the refrigerant tank during the standby mode setting, and the diluted solution concentration during proper operation based on the detected outside air temperature, and an appropriate refrigerant circulation flow rate, First control means for setting an appropriate liquid level in the refrigerant tank suitable for the outside air temperature by calculating the amount of refrigerant to be stored in the refrigerant tank, and setting the standby mode when the outside air temperature rises. The memory liquid level at the time is compared with the appropriate liquid level obtained by the calculation, and the appropriate liquid level is higher than the memory liquid level. In this case, until the storage liquid level reaches the appropriate liquid level, the pump is driven to supply the dilute solution to the regenerator to heat the dilute solution to concentrate the dilute solution. Second control means for repeating the operation of returning to the solution tank, liquefying the generated vapor refrigerant in the condenser and storing it in the refrigerant tank, and a storage liquid level when the outside air temperature is lowered and the standby mode is set. The level and the appropriate liquid level obtained by the calculation are compared, and if the appropriate liquid level is lower than the memory liquid level, the memory liquid level becomes the appropriate liquid level. An air conditioner using an absorption refrigerating machine is provided, further comprising: third control means for controlling the refrigerant in the refrigerant tank to return to the dilute solution tank.

According to yet another aspect of the present invention, the third control means in the above-mentioned main aspect is a check valve provided in a pipeline connecting the refrigerant tank and the dilute solution tank. An air conditioner using an absorption refrigerator is provided, which includes a control valve having a function.

[0024]

The present invention has the above-described structure, so that when the cooling operation is interrupted or stopped, the concentration of the absorbing liquid that absorbs the refrigerant can be kept at an ever-changing ambient temperature, and the diluted solution can be maintained. Either one of concentration and dilution is repeatedly performed.

[0025]

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

The configuration of the embodiment of the present invention shown in FIG. 1 is almost the same as the above-described example shown in FIG. 4 except for the control system, and the respective parts having the same functions are designated by the same reference numerals, and accordingly, those parts thereof are not shown. The description is omitted. Here, the control circuits necessary for controlling the operation of the device and the operation of the device are described.

In FIG. 1, T1 is a temperature sensor for detecting an intake air temperature provided in an intake duct located upstream of the evaporator 10, T2 is a temperature sensor for detecting a cooled blast temperature, and T3 is a regenerator. Level sensor for detecting the liquid level inside the tank, T4 a temperature sensor for detecting the temperature of the liquefied refrigerant at the outlet of the condenser 16, T5 a temperature sensor for detecting the outside air temperature, and T6 a liquid level in the refrigerant tank 18. It is a level sensor for detecting.

In the control circuit, in addition to the above-mentioned sensors, C
A controller 30 including a PU, a memory, and a drive circuit,
A receiver 2a of the indoor unit 2 receives a setting signal from the remote controller 6 (see FIG. 3), and a communication controller 31 that receives a signal from the receiver 2a is provided, and the controller 30 includes a temperature sensor T1 and a temperature sensor T1. Each signal (information) from T2, T4, T5 and level sensors T3, T6, and communication controller 31
Signal (information) from 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 operation of each of the adjusting valves V1 to V5 according to the operating conditions at that time. Control.

Next, the operation flow in the cooling operation of this embodiment 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 M ₂ is driven, and the pump 23 supplies the absorbing solution from the dilute solution tank 21 to the regenerator 12. (F-2). The other valves remain as they are. At this time, the CPU of the controller 30 determines whether or not the liquid level of the regenerator 12 has reached the specified level by looking at the signal from the sensor T3 (F-3).

When the liquid level reaches the 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 temperature of the condenser 16 gradually rises. The CPU of the controller 30 determines from the signal from the sensor T4 whether or not the temperature of the condenser 16 has reached a predetermined value (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 blower fan 11 and the air cooling fan 17 are rotated (F-7).

As a result, the refrigerant vapor sent from the regenerator 12 is liquefied in the condenser 16, and the liquefied refrigerant flows into the evaporator 10 due to the pressure difference between the condenser 16 and the evaporator 10. Refrigerant evaporates (evaporates) inside the evaporator 10.
However, the cooling action by the heat of vaporization occurs. As a result, the air blown from the room through the intake duct 4 by the blower fan 11 comes into direct contact with the outer surface of the evaporator 10 to be cooled. The cooled air is sent to the indoor unit 2 through the air duct 3 and is blown into the room 5 as cold air.
The cooling operation for cooling the room 5 is started (F-8).

In this cooling operation, the refrigerant vaporized in the evaporator 10 to become vapor flows into the absorber 20 and is absorbed therein by the absorbing liquid. The absorbing liquid, which has absorbed the refrigerant and has a reduced concentration, once enters the dilute solution tank 21, and then is pumped by the pump 23 through the valve V3 from the regenerator 12 in the heat exchanger 22 to generate a high-concentration absorbing liquid and heat. It is exchanged and sent again to the regenerator 12. This is the stationary mode of the cooling operation, during which the valve V5 is repeatedly opened and closed as necessary.

When the operation is stopped, the remote controller 6
Turn off the driving button (F-9). Thereby, the blower fan 11 and the air cooling fan 17 are stopped, and the burner 13 is extinguished (F-10). Meanwhile, the valves V2 and 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 to prevent the refrigerant tank 18 and the regenerator 12 from being corroded by the absorption liquid while the apparatus is stopped and to dilute the concentrated solution of the absorption liquid so as not to crystallize. Then, with a slight time delay, the pump 23 is stopped (F-11), the flow of all liquid in the entire apparatus is stopped, and only the valve V2 is opened, and the remaining valves are all closed. .

By the way, in the absorption refrigerator, when the outside air temperature is high, the higher the concentration of the absorbing liquid contained in the absorber 20, the larger the cooling capacity. In addition, the absorbing liquid deposits crystals that are harmful to the circulation of the solution and the apparatus itself depending on the relationship between the concentration and the temperature. Therefore, when the air-conditioning load in the room to be air-conditioned is large, in order to perform the air-conditioning in the optimum state from the beginning of the cooling operation, the outside air temperature that changes momentarily even when the cooling operation is interrupted or stopped. Therefore, it is necessary to set the standby mode that always maintains the maximum allowable concentration of the absorbing liquid. This standby mode is selected by an operator (user) using the remote controller 6.

The operation flow of the standby mode will be described with reference to FIG. When the standby mode switch is turned on by the remote controller 6 (S-1), the burner 13 is ignited, the outside temperature is constantly measured by the temperature sensor T5, and the actual liquid level in the refrigerant tank 18 is measured by the level sensor T6. Each level will be detected (S
-2). The detected outside air temperature information is input to the controller 30, and is suitable for the outside air temperature at that time so that the cooling operation is performed at the maximum allowable concentration at which the absorbing liquid in the absorber 20 may not crystallize at the outside air temperature at that time. The calculated refrigerant circulation amount is calculated by the controller 30 (S-3), and the set refrigerant storage amount (predetermined liquid level of the refrigerant tank 18) to be stored in the refrigerant tank 18 so as to be the appropriate refrigerant circulation amount is the controller 30. Is set by (S-4). On the other hand, the actual refrigerant storage amount in the refrigerant tank 18 can be known by detecting the liquid level in the refrigerant tank 18 with the level sensor T6, and the liquid level information detected by the level sensor T6, that is, the detected refrigerant storage amount. Information is constantly input to the controller 30 via the level sensor T6. In the controller 30, the set refrigerant storage amount based on the maximum allowable concentration according to the outside air temperature at that time and the detected refrigerant storage amount are constantly compared (S-
5).

When the detected refrigerant storage amount is larger than the set refrigerant storage amount, that is, when the concentration of the absorbing liquid is higher than the maximum allowable concentration (S-6), the valve V is set to dilute the concentration of the absorbing liquid.
4 is opened to remove the refrigerant in the refrigerant tank 18 from the dilute solution tank 21.
(S-7). When the liquid level of the refrigerant tank 18 reaches the predetermined liquid level, the valve V4 is closed. On the other hand, if the detected refrigerant storage amount is less than the set refrigerant storage amount,
That is, when the concentration of the absorbing liquid is lower than the maximum allowable concentration (S-8), the valve V2 is opened and the valve V4 is closed, and the dilute solution in the dilute solution tank 21 is supplied to the regenerator 12 by the pump 23. Then, (S-9), the liquid is heated and the absorbing liquid is concentrated. The generated vapor refrigerant is cooled in the condenser 16 (at this time, the air cooling fan 17 is rotating), liquefied and stored in the refrigerant tank 18. The concentration operation is continued until the liquid level of the refrigerant tank 18 reaches the predetermined liquid level (S-10).

In any case, when the liquid level of the refrigerant tank detected by the level sensor T6 reaches a predetermined level, that is, the set refrigerant storage based on the maximum allowable concentration corresponding to the outside air temperature at that time. When the amount has been reached, the dilution or concentration operation is terminated, and the state returns to the outside air temperature monitoring state (S-2) in the standby mode.

In the above embodiment, lithium bromide is used as the absorbing liquid and water is used as the refrigerant, but it goes without saying that the present invention is not limited to these.

[0041]

As described above, according to the present invention,
When the operator (user) starts the absorption refrigerator, the absorption liquid (concentrated solution and dilute solution) has already reached the maximum allowable concentration at the outside air temperature at that time, so there is no need to perform the concentration operation of the absorption liquid. The maximum cooling capacity suitable for the outside air temperature at the time of startup can be promptly exerted on the air conditioner.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration 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 flowchart of a standby mode in the air conditioner according to the present invention.

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

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

[Explanation of symbols]

 1 outdoor unit 2 indoor unit 3 air duct 4 air intake duct 5 chamber 6 remote controller 10 evaporator 11 air blower fan 12 regenerator 13 burner 14 fuel supply pipe 15 fuel supply control valve 16 condenser 17 air cooling fan 18 refrigerant tank 20 absorber 21 dilute solution tank 30 controller 31 communication controller T1, T2, T4, T5 temperature sensor T3, T6 level sensor V1, V2, V3, V4, V5 valve

Claims (3)

[Claims] 1. An air circulated between an air-conditioned room and an air conditioner is directly cooled via an air intake duct, a blower duct, and a blower fan provided inside either one of the ducts. An evaporator that is installed at a boundary between the intake duct and the blower duct and that is internally cooled by heat of vaporization; and an absorber that stores an absorbing liquid that absorbs vapor generated in the evaporator, A dilute solution tank for storing a dilute solution obtained by absorbing vapor in an absorber, and a regenerator for heating the dilute solution supplied from the dilute solution tank via a pump to generate a refrigerant vapor. And a condenser for delivering the liquefied refrigerant to the evaporator after liquefying the generated refrigerant vapor by cooling it,
An air conditioner using an absorption refrigerator having a refrigerant tank for refrigerant storage provided via a conduit between the condenser and the dilute solution tank, when the cooling operation is interrupted or stopped, A control mechanism for either concentrating or diluting the dilute solution is provided so that the standby mode can be maintained in which the absorption liquid can always output a concentration capable of outputting the maximum cooling capacity according to the outside air temperature. An air conditioner characterized by that. 2. The remote control operation switch for selecting the standby mode, the temperature sensor for detecting the outside air temperature and outputting the detection result, the control mechanism, and the liquid level in the refrigerant tank when the standby mode is set. Means for detecting and storing the level, and for calculating the diluted solution concentration during proper operation, the proper refrigerant circulation flow rate, and the refrigerant amount to be stored in the refrigerant tank based on the detected outside air temperature. Thus, the first control means for setting an appropriate liquid level in the refrigerant tank suitable for the outside air temperature, the stored liquid surface level when the outside air temperature rises and the standby mode is set, and the calculated liquid level When the appropriate liquid level is higher than the memory liquid level, the memory liquid level is compared to the appropriate liquid level. To date, concentrating the rare-solution was heated while supplying the diluted solution to the regenerator to drive the pump,
Second control means for repeating the operation of returning the concentrated liquid to the dilute solution tank, liquefying the generated vapor refrigerant in the condenser and storing it in the refrigerant tank, and setting the standby mode when the outside air temperature decreases The memory liquid level at the time is compared with the appropriate liquid level obtained by the calculation, and when the appropriate liquid level is lower than the memory liquid level, the memory liquid level is said to be suitable. An air conditioner using an absorption chiller, comprising: third control means for controlling the refrigerant in the refrigerant tank to return to the dilute solution tank until the liquid level is reached. 3. The absorption refrigeration system according to claim 3, wherein the third control means includes a control valve having a check valve function, which is provided in a pipe line connecting the refrigerant tank and the dilute solution tank. Air conditioner using a machine.