JPH06235559A - Method and apparatus for controlling operation of air conditioning plant using absorption type refrigerator - Google Patents

Abstract

PURPOSE:To sufficiently exhibit the functions of a refrigerating machine by controlling the concentration of an absorbing liquid in relation to the outside air temperatures. CONSTITUTION:An absorbing liquid containing a lithium-bromide aqueous liquid as the main component is used and water is used as cooling medium. To cool the room air directly, an evaporator 15 is installed in an air duct through which the room air to be cooled passes, and the cooled air is directly blown into a room through the duct to carry out cooling operation. In addition, air cooling method is applied to the temperature control of the refrigerant in an absorber 22. In this case, the amount of refrigerant to be stored in a refrigerant reservoir 13 is controlled in relation to the outside air temperatures, so that an air conditioning plant is operated while the absorbing liquid is always kept at a high concentration within a range the absorbing liquid does not reach the crystallization temperature. Therefore, the functions of a refrigerator can be exhibited sufficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control method for an air conditioner and an apparatus for the same, which uses an absorption refrigerator for a general house or a small building.

[0002]

2. Description of the Related Art In a cooling system using an absorption refrigerator, a refrigerant vapor evaporated in a regenerator is condensed in a water-cooled condenser, and the condensed liquid refrigerant is guided to an evaporator to produce a fan coil unit in a room. Heat medium (normal water) that circulates between the refrigerator and the refrigerator
Is cooled by latent heat of vaporization, while the evaporated refrigerant vapor is absorbed in a concentrated solution (absorption liquid) by a water-cooled absorber and returned to the regenerator. And
In the case of this absorption refrigerator, the temperature of the cooling / heating medium circulated in the indoor fan coil unit is cooled to around 7 ° C. in the evaporator, and this cooling / heating medium is circulated in the indoor fan coil unit to cool the indoor air. It is then returned to the evaporator at around 12 ° C. For this reason, when using an aqueous solution of lithium bromide as the absorbing liquid, it is necessary to keep the temperature of the absorbing liquid in the absorber at around 40 ° C. To maintain this temperature, install a cooling tower on the rooftop, etc. A circuit cooling method is adopted.

[0003]

However, the air conditioner using the conventional absorption chiller adopting such a water cooling system has the following drawbacks. a. Since the absorber is temperature-controlled (cooled) by a water-cooling system, the equipment becomes large and a lot of construction costs are required for piping and the like, which is disadvantageous for cooling a general house or a small building. b. Since it is necessary to connect the indoor fan coil unit and the refrigerator with a pipe for circulating the cooling / heating medium, the construction cost and equipment cost are high. c. Among absorption type refrigerators, there is known an ammonia absorption type refrigerator in which ammonia water is used as an absorption liquid and ammonia is used as a refrigerant. If this refrigerator is a small one,
There is one that cools the absorber by an air cooling method. However, in the case of this method, water is used as the cooling / heating medium circulating between the fan coil unit and the evaporator in the room. The reason for this is to prevent the leaked ammonia from flowing into the room in the unlikely event that ammonia leaks. For this reason, even in the case of an ammonia absorption refrigerator that cools the absorber by air cooling, a system in which a cooling / heating medium is circulated between the fan coil unit and the evaporator in the room has a problem in this piping. Further, in an absorption refrigerator using an aqueous solution of lithium bromide, in order to air-cool the absorber, it is necessary to have a very large heat radiation area, which is not suitable for a house or a small building. d. On the other hand, there is known a so-called package type absorption gas air conditioner in which indoor air is directly cooled by an evaporator. However, in the case of this gas air conditioner, the cooling of the absorber and the condenser is a water cooling system, and this example also has a problem in piping. e. By the way, when operating an absorption chiller, the concentration of the absorption liquid is an important factor for satisfactorily exerting its function. For example, if the concentration of the absorption liquid becomes high,
The evaporation temperature of the liquid refrigerant can be kept low without lowering the temperature of the absorbing liquid so much, but at the same time, there is a high risk that the absorbing liquid will cause crystallization. Therefore, in the air-cooled absorption refrigerator, when the outside air temperature rises, the point is how to operate at a high concentration while preventing the absorption liquid from crystallizing.

An object of the present invention is to provide an air-conditioning method and apparatus using an air-cooling type absorption refrigerating machine which can be put into practice for small-scale buildings including general houses. It is an object to propose a control method and an apparatus for performing an operation while constantly exerting its function satisfactorily while changing the liquid concentration.

The air-conditioning method using the absorption refrigerating machine proposed in the present invention and the structure of the apparatus are as follows.

1. Using an aqueous solution containing lithium bromide as the main component as the absorbing liquid, using water as the refrigerant, and directly cooling the indoor air by positioning the evaporator in the passage through which the room air to be cooled passes, and this cooled In an air conditioner that uses an absorption refrigerator to cool the air by directly blowing the cool air into the room through a duct to control the temperature of the absorbing liquid in the absorber, By controlling the amount of refrigerant stored in the refrigerant sump in relation to the temperature, an absorption refrigerator that operates while always maintaining a high concentration of the absorption liquid within the range where the absorption liquid does not reach the crystal temperature A method for controlling the operation of an air conditioner using the method.

2. A regenerator that generates a refrigerant vapor by heating a dilute solution in which water as a refrigerant is absorbed by an absorption liquid containing an aqueous solution of lithium bromide as a main component, a condenser that condenses the generated refrigerant vapor by an air cooling method, and an object to be cooled. An evaporator installed in a passage through which indoor air passes, an absorber configured to be air-cooled by a blower fan, a refrigerant liquid pool installed between the condenser and the evaporator, and the absorber being air-cooled. Of the outside air temperature to be detected, the controller for controlling the concentration of the absorbing liquid by controlling the amount of the refrigerant stored in the refrigerant liquid reservoir by the outside air temperature, and of the air conditioner using an absorption refrigerator Operation control device.

The working fluid in the regenerator is heated in the regenerator by, for example, a gas burner to generate a refrigerant vapor, which is separated by a separator and reaches a condenser, where it is cooled and condensed by an air cooling method. And then to the evaporator. Outside the evaporation tube inside the evaporator, warm the room inside the
℃ air is circulating. When the refrigerant liquid evaporates in the evaporation cylinder, this latent heat cools the room air at 27 ° C to about 15 ° C and blows it indoors via the duct. The refrigerant vapor evaporated in the evaporator is guided to the absorber, where it is absorbed by the absorbing liquid (concentrated solution). This absorbing action is an exothermic reaction, and the absorbing liquid is cooled by air. The more sufficiently the absorption liquid is cooled and the temperature is lowered, and the higher the concentration of the absorption liquid is, the lower the evaporation temperature of the refrigerant in the evaporator is.

Since this absorption refrigerating machine does not generate cold water of 7 ° C., but needs to cool the room air to about 15 ° C.,
It is sufficient if the temperature of the absorbing liquid in the absorber is cooled to about 50 ° C. Therefore, the function as a refrigerator can be exhibited only by air-cooling the absorber with the air having an outside air temperature of about 35 ° C in summer. The working fluid (dilute solution) that has absorbed the refrigerant vapor in the absorber returns to the regenerator again.

In the cooling cycle, the temperature of the absorbing liquid is the lowest around the air-cooled absorber. As a matter of course, since it is air-cooled, the absorption liquid cannot fall below the outside air temperature. Therefore, the controller detects the outside air temperature for air cooling and raises the concentration of the absorbing liquid (concentrated solution) to a concentration that does not crystallize at this outside air temperature, eliminating the concern of absorbing liquid crystals and at the time of high outside air temperature. Also, the evaporation temperature of the evaporator can be kept low.

Specifically, when the outside air temperature is high, the refrigerant storage amount in the refrigerant reservoir is increased to increase the concentration of the absorbing liquid.

This control may be a step control such as a three-step switching system of high / medium / low concentration, or a continuous control system for the concentration of the absorbing liquid.

[0011]

EXAMPLE FIG. 1 shows an air conditioner using a single-effect absorption refrigerator according to the present invention. Reference numeral 1 is an air conditioner main body, 2 is a house, 3 is a chimney, 4 is an indoor air blow duct, and 5 is an intake duct. The detailed structure of the air conditioner main body 1 is shown in FIG.

In FIG. 2, 6 is a fuel supply line, and 7 is a combustion control valve for opening / closing and adjusting the fuel. 8 is a burner, 9 is a regenerator, an aqueous solution of lithium bromide is used as an absorbing liquid, and water is used as a refrigerant. The refrigerant vapor generated in the regenerator 9 is separated by the separator 9a and then guided to the condenser 11 via the pipe line 10, where it is air-cooled by the blower fan 12 to be condensed and stored in the refrigerant liquid reservoir 13. It is stored once. The refrigerant in the refrigerant reservoir 13 is guided to the distribution pipe 16 of the evaporator 15 via the pipe 14, and the distribution pipe 16 serves as a fin.
It flows down in a large number of evaporation cylinders 17 with 18. The evaporator 15 is located in the heat exchange chamber 19, the inlet 20 of the heat exchange chamber 19 is connected to the intake duct 5, the outlet 21 is connected to the air duct 4, and the air in the cooling target room 2a in the house 2 is Is forcedly convected by the fan 20a. As a result, the refrigerant flowing down in the evaporation cylinder 17 is heated by the air directly sucked from the room and evaporated, and the latent heat of evaporation cools the indoor air. Cooled air exit
21 from the blower duct 4 to the outlet 4a to the room 2a
Be blown to. Here, as an example of the temperature, when the temperature of the air in the room 2a is 27 ° C, the temperature of the air that is cooled and blown from the outlet 4a to the room 2a is 15 ° C.

The refrigerant vapor exiting the evaporator 15 enters a large number of absorption cylinders 23 with fins 25. On the other hand, the absorption liquid heated by the regenerator 9 and separated by the separator 9 a is guided to the absorption liquid injection port (nozzle) 24 via the pipe 26, and enters the absorption cylinder 23 there. The absorption cylinder 23 is devised so that the absorption liquid flows down in a film shape along the inner wall surface thereof, and as a result, the absorption area is widened. Further, the absorption cylinder 23 is structured to be air-cooled by the blower fan 12 described above. Here, the absorption liquid is air-cooled at around 50 ° C.

The absorbing liquid (dilute solution) that has absorbed the refrigerant vapor in the absorbing cylinder 23 is collected in the collecting pipe 27 and returns to the regenerator 9 via the pipe 28. Reference numeral 29 is a circulation pump, and 30 is a heat exchanger, which has a function of heating a dilute solution with a concentrated solution.

FIG. 3 shows an embodiment of the evaporator 15 and the absorber 22. The refrigerant liquid introduced into the distribution pipe 16 is
At that time, the air flows into a large number of evaporation tubes 17 and is heated by the air in the room flowing outside the evaporation tubes 17 to be evaporated, and the indoor air is cooled by this latent heat of evaporation. The evaporated vapor of refrigerant enters the absorption cylinder 23 that follows the evaporation cylinder, where the absorption liquid injection port (nozzle)
It is absorbed by the absorption liquid injected from 24. The outside of the absorption cylinder 23 is forcedly cooled by the blower fan 12. The hydraulic fluid that has left the absorption cylinder 23 is collected in the liquid collection pipe 27 and then returns to the regenerator 9. The working fluid in the collecting pipe 27 is stored in the lower half of the pipe,
The upper half is in the gas phase, and the refrigerant vapor that has reached the inside of the collecting pipe 27 without being absorbed in any of the absorption tubes 23 enters the other absorption tube 23 from this gas phase, Absorbed by. In the embodiment, the evaporation cylinder 17 of the evaporator 15 is inclined, but it is possible to make it vertical by devising the structure inside the cylinder.

Reference numeral 31 denotes a controller, which generates a control signal for opening either the valve 33 or the valve 34 on the basis of an outside air temperature input signal from an outside air temperature sensor 32.

Next, the contents of the control will be described with reference to an embodiment.

In the embodiment, the concentration difference between the concentrated solution of the absorbing solution and the dilute solution is 4%.

The concentration (%) of the absorbing liquid and the crystallization temperature (° C)
Table 1 shows the relationship between and the evaporation temperature of the refrigerant that equilibrates when the temperature reaches a certain temperature.

[0020]

[Table 1]

Now, dilute solution 58%, concentrated solution 62%, valve 33
Is opened, and the liquid level of the refrigerant reservoir is assumed to be A in FIG. Since the crystal temperature of the concentrated solution is 25 ° C, the outside temperature is 25
If it is above ℃, there is no worry of crystals. Therefore, if the temperature of the absorbing liquid is kept at 46 ° C, the evaporator temperature can be kept at 9 ° C.

Next, assume that it becomes difficult to keep the temperature of the absorbing liquid at 46 ° C., for example, when the outside air temperature exceeds 35 ° C. In this state, change the cycle to 60% dilute solution and 64% concentrated solution.

In the above control, when the outside air temperature exceeds the set value,
The valve 33 is closed, the valve 34 is opened, the liquid level of the refrigerant reservoir rises to B in FIG. 2, and the amount of the refrigerant stored in the refrigerant reservoir 13 increases, so that the concentration of the absorbing liquid in the operation cycle increases. .

By performing such control, the dilute solution concentration
When it rises to 60%, as shown in Table 1, the temperature of the absorbing liquid increases.
Even if the temperature rises to 50 ° C, the temperature of the evaporator can be kept at 9 ° C. On the contrary, when the outside air temperature is lower than the set value, the reverse control is performed to reduce the concentration of the absorbing liquid.

Although the above-mentioned embodiment uses a single-effect absorption refrigerator, the present invention can be applied to a double-effect absorption refrigerator as it is.

As described above, according to the present invention, the concentration of the absorbing liquid is controlled in relation to the outside air temperature in the air-conditioning method and the apparatus using the absorption type refrigerator adopting the air cooling system. It is possible to operate the absorber at the air-cooling temperature and to fully realize the function of the refrigerator while avoiding the risk of.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an air conditioner using an absorption refrigerator according to the present invention.

FIG. 2 is an explanatory view of the structure and operation of an absorption refrigerator according to the present invention.

FIG. 3 is an explanatory diagram of an evaporator and an absorber.

[Explanation of symbols]

 1 Air conditioner body 2 House 3 Chimney 4 Blower duct 5 Intake duct 6 Fuel supply line 7 Fuel control valve 8 Burner 9 Regenerator 9a Separator 10 Pipeline 11 Condenser 12 Blower fan 13 Refrigerant reservoir 14 Pipeline 15 Evaporator 16 minutes Piping 17 Evaporation tube 18 Fin 19 Heat exchange chamber 20 Inlet 21 Outlet 22 Absorber 23 Absorption tube 24 minutes Piping 25 Fin 26 Pipe line 27 Liquid collection pipe 28 Pipe line 29 Circulation pump 30 Heat exchanger 31 Controller 32 Outside temperature detection sensor 33 valve 34 valve

Claims (4)

[Claims] 1. An absorbent containing an aqueous solution of lithium bromide as a main component is used, water is used as a refrigerant, and an evaporator is positioned in a passage through which the indoor air to be cooled is cooled to cool the indoor air directly. , The cooling air is blown directly into the room through a duct for cooling, and the temperature of the absorbing liquid in the absorber is controlled by an air cooling system. In an air conditioner, by controlling the amount of refrigerant stored in the refrigerant reservoir in relation to the outside air temperature, operation is performed while maintaining a high concentration of the absorbing liquid within the range where the absorbing liquid does not reach the crystal temperature. An operation control method for an air conditioner using an absorption refrigerator. 2. A regenerator for generating a refrigerant vapor by heating a dilute solution in which water as a refrigerant is absorbed in an absorbent containing an aqueous solution of lithium bromide as a main component, and a condensing condenser for condensing the generated refrigerant vapor by an air cooling method. A condenser, an evaporator incorporated in a passage through which air in the room to be cooled passes, a refrigerant liquid reservoir incorporated between the condenser and the evaporator, and an absorber configured to be air-cooled by a blower fan, A controller for detecting the outside air temperature for air-cooling the absorber, controlling the amount of the refrigerant stored in the refrigerant liquid reservoir by the outside air temperature to control the concentration of the absorbing liquid, and an absorption refrigerator comprising: Operation control device for air conditioners. 3. A method for controlling the operation of an air conditioner using the absorption refrigerating machine according to claim 1, which is carried out using a single-effect absorption refrigerating machine. 4. An operation control device for an air conditioner using the absorption refrigerating machine according to claim 1 or 2, which is carried out using a double-effect absorption refrigerating machine.