JP2902305B2 - Absorption air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption type air conditioner capable of cooling and heating a room using an absorption type refrigeration cycle.

[0002]

2. Description of the Related Art The basic structure of an absorption refrigeration cycle is as follows.
A regenerator that heats the absorbing liquid and vaporizes a part of the absorbing liquid,
A condenser that cools and liquefies the vaporized refrigerant generated in the regenerator, an evaporator that evaporates the liquefied refrigerant liquefied by the condenser under low pressure, and absorbs the vaporized refrigerant evaporated by the evaporator into an absorbing liquid. The absorbing liquid, which includes an absorber and absorbs the vaporized refrigerant by the absorber, is sent to a regenerator by a solution pump. When the refrigerant evaporates in the evaporator, latent heat is taken from a heat medium (water or the like) sent from the evaporator to the indoor heat exchanger via the heat medium circuit. The heat medium that has been deprived of heat and cooled is sent to the indoor heat exchanger and exchanges heat with the indoor air to cool the room.

During the cooling operation, the absorption liquid inside the absorption refrigeration cycle becomes high in concentration due to low concentration of low concentration absorption liquid (for example, absorption liquid sent from an absorber to a regenerator) or refrigerant. High-concentration absorbing liquid (for example, absorbing liquid sent from the regenerator to the absorber). Absorbents with higher concentrations crystallize at higher temperatures than absorbers with lower concentrations. If the absorption liquid crystallizes inside the absorption refrigeration cycle, the absorption liquid will not flow through the crystallized part, and the absorption refrigeration cycle will not be able to operate, and if the absorption refrigeration cycle is continued, the cycle may be damaged. There is also. For this reason, when the cooling operation is stopped, it is necessary to perform the dilution operation for operating the solution pump and making the concentration of the absorbing solution uniform while the operation of the heating means for heating the absorbing solution is stopped.

[0004]

In the cooling operation using the absorption refrigeration cycle, the cooling operation is performed by utilizing the concentration difference of the absorption liquid. For this reason, after the cooling operation is stopped, if the concentration of the absorbing solution is made almost uniform by the dilution operation, the next time the cooling operation is started, it takes time until a sufficient concentration difference occurs in the absorbing solution, and the cooling operation has to be started. The rise becomes worse. Conversely, if the cycle is stopped with a concentration difference remaining in the absorbent to improve the rise of cooling, for example, during winter, the environmental temperature at which the absorption refrigeration cycle is installed will decrease, and , The temperature of the relatively high-absorbent solution also decreases, and the relatively high-absorbent solution crystallizes.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an object to provide an excellent cooling start-up when cooling is performed continuously in summer or the like, and to install an absorption refrigeration cycle in winter. It is an object of the present invention to provide an absorption air conditioner in which crystallization of an absorption liquid does not occur in an absorption refrigeration cycle even when the environmental temperature is reduced.

[0006]

[Means of claim 1]

The absorption-type air conditioner includes: a) heating means for heating the absorption liquid; b) a regenerator for heating the absorption liquid with the heating means to vaporize a part of the absorption liquid; A condenser that cools and liquefies, an evaporator that evaporates the liquefied refrigerant liquefied by the condenser under low pressure, an absorber that absorbs the vaporized refrigerant evaporated by the evaporator into an absorbent, and an absorbent that absorbs the liquid in the absorber. An absorption refrigeration cycle having a solution pump for pumping to the regenerator; c) an indoor heat exchanger installed inside the room for exchanging heat between indoor air and a heat medium, and when the liquefied refrigerant evaporates in the evaporator. A heat medium circuit that guides the heat medium cooled by the deprivation of latent heat of evaporation to the indoor heat exchanger and guides the heat medium heat-exchanged with the indoor air to the evaporator again to the evaporator; Provided in the circuit and circulated heat medium D) when the cooling operation is stopped, the solution pump is operated while the heating means is stopped to circulate the refrigerant and the absorbing liquid in the absorption refrigeration cycle. During the operation stop, the absorbent having a high concentration in the absorption refrigeration cycle,
First dilution operation means for diluting to a concentration that does not crystallize at a predetermined absorption liquid temperature; e) absorption liquid temperature detection means for detecting the temperature of the highly concentrated absorption liquid in the absorption refrigeration cycle while the operation is stopped; ) Heating operation means for guiding the absorbing liquid heated by the heating means directly to the evaporator and heating a heating medium flowing through the evaporator to perform indoor heating; and g) final operation state of the absorption refrigeration cycle. H) the last operation state stored in the operation state storage means is a cooling operation, and the temperature of the absorption liquid detected by the absorption liquid temperature detection means is equal to or higher than the predetermined absorption liquid temperature. When the temperature decreases to the predetermined dilution start temperature set in the above, the solution pump is operated in a state where the heating means is stopped, and the refrigerant and the absorbent in the absorption refrigeration cycle are circulated, and the absorption liquid is cooled. Second dilution operation means for making the concentration substantially uniform.

According to a second aspect of the present invention, in the absorption type air conditioner of the first aspect, the absorption liquid temperature detecting means is an outside air temperature sensor for detecting an environmental temperature in which the absorption refrigeration cycle is installed, When the ambient temperature detected by the outside air temperature sensor decreases to a predetermined dilution start temperature while the operation is stopped, the dilution operation means determines that the temperature of the highly concentrated absorbent in the absorption refrigeration cycle has also decreased to the predetermined dilution start temperature. It is characterized by making a judgment.

[0008]

[0009] [Claim 3] In the absorption type air conditioner according to claim 1 or 2, the heating operation means includes a heating pipe for guiding the absorbent heated by the heating means to the evaporator; A heating valve that opens the heating pipe during the heating operation, wherein the second dilution operation means opens the heating valve when the concentration of the absorbing solution is made uniform.

[0010] In the absorption air conditioner according to any one of claims 1 to 3, the operating state storage means is a storage means using a nonvolatile memory.

[0011]

[Action and effect of the invention]

[Function of Claim 1] During the cooling operation, in the regenerator of the absorption refrigeration cycle, the absorption liquid is heated by the heating means to generate vaporized refrigerant and increase the concentration of the absorption liquid. The vaporized refrigerant is condensed in the condenser and becomes a liquefied refrigerant. The liquefied refrigerant evaporates by removing vaporization heat from the heat medium flowing through the evaporator. The refrigerant vaporized by the evaporation is absorbed by the absorbent having a high concentration in the absorber. Then, the absorbing liquid whose concentration has been lowered by absorbing the refrigerant is sent from the absorber to the regenerator by the solution pump, and the above cycle is repeated.

When the cooling operation is stopped, the solution pump is operated by the first dilution operation means while the heating means is stopped, and the high concentration absorbent in the absorption refrigeration cycle is cooled to a predetermined absorbent temperature (for example, (The lowest temperature during a period in which cooling is frequently performed such as in summer) to a concentration that does not crystallize (first dilution operation).

After the cooling operation, the environmental temperature at which the absorption refrigeration cycle is installed decreases due to the change of seasons, etc., and the temperature detected by the absorption liquid temperature detecting means is set to a predetermined dilution start temperature (above a predetermined absorption liquid temperature). If the previous operation state stored in the operation state storage means is cooling, the second dilution operation means operates the solution pump in a state in which the heating means is stopped, The refrigerant and the absorption liquid in the absorption refrigeration cycle are circulated to make the concentration of the absorption liquid substantially uniform (second dilution operation).

In the absorption air conditioner of the present invention, the first dilution operation performed when the cooling operation is stopped is a dilution operation in which a concentration difference is left in the absorption liquid in the absorption refrigeration cycle. In addition, the crystallization of the absorbing solution is prevented, and the next start of cooling is improved. The second dilution operation performed when the environmental temperature at which the absorption refrigeration cycle is installed is lowered and the previous operation is the cooling operation is a dilution operation that makes the concentration of the absorbent in the absorption refrigeration cycle substantially uniform,
Prevents the absorption liquid from crystallizing in the absorption refrigeration cycle even when the environmental temperature is extremely low. When the heating operation is performed by the absorption refrigeration cycle, the concentration of the absorption liquid in the absorption refrigeration cycle becomes substantially uniform. Therefore, during operation stop,
Even if the temperature of the absorbent in the absorption refrigeration cycle drops to the predetermined dilution start temperature, the second dilution operation is not performed if the previous operation stored in the operation state storage means is the heating operation. Thus, when the previous operation state is the heating operation,
Since the useless second dilution operation is not performed, useless energy consumption can be suppressed.

When the environmental temperature at which the absorption refrigeration cycle is installed decreases during operation stoppage, the temperature of the refrigerant in the absorption refrigeration cycle also decreases as the environmental temperature decreases. When the ambient temperature detected by the outside air temperature sensor decreases to the predetermined dilution start temperature during the operation stop, it is determined that the temperature of the highly concentrated absorbent in the absorption refrigeration cycle has also decreased to the predetermined dilution start temperature. The second dilution operation means performs the second dilution operation to make the concentration of the absorption liquid in the absorption refrigeration cycle substantially uniform. When the environmental temperature decreases, the environmental temperature decreases before the temperature of the absorbent in the absorption refrigeration cycle. On the other hand, the temperature of the absorbent in the absorption refrigeration cycle may have a different rate of decrease depending on the position at which the absorbent is detected. For this reason, by detecting the environmental temperature and performing the second dilution operation, crystallization of the absorbent in the absorption refrigeration cycle can be reliably prevented.

[0016]

[Function and Effect of Claim 3] The second dilution operation means opens the heating valve when making the concentration of the absorbing solution uniform. Then, the absorbent having a relatively high concentration in the regenerator is guided to the evaporator and the absorber through the heating pipe. In the evaporator, a refrigerant is present, and in the absorber, an absorbing liquid having a relatively low concentration after absorbing the vaporized refrigerant is present. Therefore, the high-concentration absorbing liquid supplied from the heating pipe is mixed with the refrigerant and the low-concentration absorbing liquid, and is again guided to the regenerator by the solution pump. As described above, by opening the heating valve, the circulation of the absorbing liquid in the absorption refrigeration cycle is promoted, and the time required for equalizing the absorbing liquid can be shortened.

[Operation and Effect of Claim 4] The operating state storage means can store the previous operating state with a simple circuit by using a nonvolatile memory.

[0019]

Next, an absorption type air conditioner of the present invention will be described based on an embodiment shown in the drawings. FIG. 1 and FIG. 2 show an embodiment, and FIG. 1 is a schematic configuration diagram of an absorption air conditioner using a double effect absorption refrigeration cycle for performing indoor air conditioning. The absorption type air conditioner 1 of the present embodiment is roughly divided into a heating means 2 for heating an absorbing liquid (a lithium bromide aqueous solution in this embodiment).
A double-effect absorption refrigeration cycle 3, and indoor air-conditioning means 4 for air-conditioning the room with cold / hot water cooled or heated by the absorption refrigeration cycle 3 (the heat medium of the present invention, water in this embodiment). And a cooling water cooling means 5 for cooling cooling water mainly used for cooling a vaporized refrigerant (steam in this embodiment) in the absorption refrigeration cycle 3, and a control device for controlling each mounted electric functional component And 6.

[Explanation of the Heating Means 2] The heating means 2 of this embodiment is a gas combustion device which burns a gas as a fuel to generate heat and heats the absorbing liquid by the generated heat. The gas burner 11 includes a gas supply unit 12 that supplies gas to the gas burner 11, a combustion fan 13 that supplies air for combustion to the gas burner 11, and the like.
Then, the heat obtained by the gas combustion of the gas burner 11 heats the boiler 14 of the absorption refrigeration cycle 3, and the boiler 14
It is provided so as to heat the low-concentration absorbing solution inside.

[Description of Absorption Refrigeration Cycle 3] The absorption refrigeration cycle 3 is provided with a boiler 14 heated by the heating means 2, and the low-concentration absorption liquid in the boiler 14 is heated to reduce the concentration of the low-concentration absorbent. A high-temperature regenerator 15 that vaporizes (evaporates) the refrigerant (water) contained in the absorption liquid to convert the low-concentration absorption liquid into a medium-concentration absorption liquid, and uses the heat of condensation of the vaporized refrigerant in the high-temperature regenerator 15 to form a medium. A low-temperature regenerator 16 that heats the concentration absorbing liquid to vaporize a refrigerant contained in the medium-concentration absorbing liquid to convert the medium-concentration absorbing liquid into a high-concentration absorbing liquid; A condenser 17 for cooling and liquefying the water vapor), an evaporator 18 for evaporating the liquefied refrigerant (water) liquefied in the condenser 17 under a pressure close to vacuum,
An absorber 19 for absorbing the vaporized refrigerant evaporated in the evaporator 18 into the high-concentration absorbent obtained in the low-temperature regenerator 16.

[Explanation of high-temperature regenerator 15] High-temperature regenerator 15
Is provided with the boiler 14 for heating the low concentration absorbing liquid by the heating means 2 as described above. The low-concentration absorbing liquid boiled by the boiler 14 is blown into a cylindrical high-temperature regeneration vessel 22 from a blow-off cylinder 21 extending upward from the boiler 14. The high-temperature, low-concentration absorbent blown into the high-temperature regeneration container 22 collides with a baffle 23 for gas-liquid separation. Then, the low-concentration absorbing liquid blown out into the high-temperature regeneration container 22 is partially evaporated to become a vaporized refrigerant, and the remaining liquid drops around the blowing cylinder 21 to become a medium-concentration absorbing liquid. Note that the vaporized refrigerant is deprived of heat by the wall of the high-temperature regenerating container 22 as heat of vaporization during evaporation of the medium-concentration absorbent in the low-temperature regenerator 4, and is cooled to become a liquefied refrigerant (water).

A liquefied refrigerant (water) is contained in the high-temperature regeneration vessel 22.
A partition tube 24 is provided between the blow-out tube 21 and the high-temperature regeneration container 22 in order to separate the high-concentration absorbent from the medium-concentration absorbent.
The liquefied refrigerant (water) cooled and liquefied in the high-temperature regeneration container 22 and separated outside the partition tube 24 is supplied to the condenser 17 through a liquid refrigerant pipe 25 connected to the lower part. The medium-concentration absorbing liquid separated between the inside of the partition tube 24 and the blow-out tube 21 is supplied to the low-temperature regenerator 16 through a middle liquid pipe 26 connected to the lower part. The middle liquid pipe 26 is provided with a throttle means 27 such as an orifice. When the cooling / heating switching valve 55 to be described later is closed,
When the pressure difference between the high-temperature regenerator 15 and the low-temperature regenerator 16 is maintained, the medium-concentration absorbing liquid flows, and when the cooling / heating switching valve 55 is opened, the medium-concentration absorbing liquid hardly flows.

[Explanation of the low-temperature regenerator 16]
Is provided with a cylindrical low-temperature regeneration container 31 covering the high-temperature regeneration container 22, and injects the medium-concentration absorption liquid supplied through the middle liquid pipe 26 toward the ceiling of the high-temperature regeneration container 22. . Since the temperature in the low-temperature regeneration container 31 is lower than the temperature of the high-temperature regeneration container 22, the pressure in the low-temperature regeneration container 31 is lower than the pressure in the high-temperature regeneration container 22. For this reason, the medium-concentration absorbing liquid supplied from the medium liquid pipe 26 into the low-temperature regeneration container 31 is easily evaporated. Then, when the medium-concentration absorbent is injected into the ceiling of the high-temperature regeneration container 22, the medium-concentration absorption is heated by the walls of the high-temperature regeneration container 22, and a part of the refrigerant contained in the medium-concentration absorption is evaporated. It becomes a vaporized refrigerant, and the rest becomes a high concentration absorbing liquid.

Here, the upper portion of the low-temperature regeneration container 31 communicates with the upper portion of the condensing container 32 in the shape of an annular container through a communication portion 33. Therefore, the vaporized refrigerant evaporated in the low-temperature regeneration container 31 is supplied into the condensation container 32 through the communication portion 33. On the other hand, the high-concentration absorbing liquid falls to the lower part of the low-temperature regeneration vessel 31 and is supplied to the absorber 19 through the high-liquid pipe 34 connected to the lower part of the low-temperature regeneration vessel 31. A ceiling plate 35 is provided above the low-temperature regeneration container 31, and a gap 36 through which the vaporized refrigerant passes is provided between the outer peripheral end of the ceiling plate 35 and the low-temperature regeneration container 31.

[Explanation of the Condenser 17] The condenser 17 is covered by a condensing container 32 having an annular container shape. Inside the condensing container 32, a condensing heat exchanger 37 for cooling and liquefying the vaporized refrigerant in the condensing container 32 is arranged. The condensing heat exchanger 37 is an annular coil through which cooling water flows. The liquefied refrigerant supplied from the low-temperature regenerator 16 into the condensing container 32 is supplied to the condensing heat exchanger 3.
The mixture is cooled and liquefied by 7 and dropped below the condensing heat exchanger 37.

On the other hand, a refrigerant is supplied to the lower side of the condensing container 32 from the high-temperature regenerator 15 through the liquid refrigerant pipe 25. When the supplied refrigerant is supplied into the condensing container 32, the pressure difference (the pressure inside the condensing container 32 is about 70 mmHg).
From low pressure), the mixture is reboiled, and supplied in a state where the vaporized refrigerant and the liquefied refrigerant are mixed. Further, a low-liquid supply pipe 38 that guides the liquefied refrigerant to the evaporator 18 is connected to the condensation container 32. The low liquid supply pipe 38 has a refrigerant valve 3 for adjusting the supply amount of the liquefied refrigerant supplied from the condensation container 32 to the evaporator 18.
9 are provided.

[Explanation of the evaporator 18] The evaporator 18 is provided below the condensing container 32 together with the absorber 19, and is formed by an annular-shaped evaporative absorption container 41 provided around the low-temperature regeneration container 31. Covered. An evaporation heat exchanger 42 for evaporating the liquefied refrigerant supplied from the condenser 17 is disposed outside the inside of the evaporation absorption container 41. This evaporating heat exchanger 42 is an annular coil,
Heat medium (cold and hot water) supplied to the indoor air-conditioning means 4 inside
Flows. The liquefied refrigerant supplied from the condenser 17 via the low liquid supply pipe 38 is sprayed onto the evaporating heat exchanger 42 from the refrigerant spraying tool 43 disposed above the evaporating heat exchanger 42. .

Since the inside of the evaporative absorption container 41 is kept substantially at a vacuum (for example, 6.5 mmHg), it has a low boiling point, and the liquefied refrigerant sprayed to the evaporating heat exchanger 42 is very easy to evaporate. Then, the liquefied refrigerant sprayed to the evaporating heat exchanger 42 evaporates by taking heat of vaporization from the heat medium flowing in the evaporating heat exchanger 42. As a result, the heat medium flowing in the evaporating heat exchanger 42 is cooled. Then, the cooled heat medium is guided to the indoor air conditioner 4 to cool the room.

[Description of Absorber 19] The absorber 19 is covered with the evaporation absorption container 41 as described above. The absorber 19 is provided inside the evaporative absorption container 41 with the high liquid pipe 3.
An absorption heat exchanger 44 for cooling the high-concentration absorption liquid supplied from 4 is arranged. This absorption heat exchanger 44
Cooling water for cooling the high-concentration absorbing liquid sprayed on the coil is supplied inside the annular coil. After passing through the heat exchanger 44 for absorption, the cooling water passes through the heat exchanger 37 for condensation of the condenser 17 and is guided to the cooling water cooling means 5 to be cooled. Then, the cooling water cooled by the cooling water cooling means 5 is guided again to the absorption heat exchanger 44.

On the other hand, above the absorption heat exchanger 44, an absorption liquid spraying device 45 for spraying the high concentration absorption liquid supplied from the high liquid pipe 34 to the absorption heat exchanger 44 is arranged. The high-concentration absorbing liquid sprayed on the absorption heat exchanger 44 passes through the coil surface of the absorption heat exchanger 44 and falls from above to below while evaporating generated by evaporation in the evaporation heat exchanger 42. Absorbs refrigerant. As a result, the evaporation absorption container 41
Absorbent liquid that has fallen to the bottom of the container becomes a low-concentration absorbent liquid with a reduced concentration. At the bottom of the evaporative absorption container 41, the evaporative absorption container 4
A low liquid pipe 46 for supplying the low concentration absorbing liquid at the bottom of 1 to the boiler 14 is connected. The low-liquid pipe 46 is provided with a solution pump 47 for flowing the low-concentration absorption liquid from the evaporation absorption container 41 in a substantially vacuum state toward the boiler 14.

[Explanation of Other Components in Absorption Refrigeration Cycle 3] Reference numeral 51 shown in FIG. 1 designates a medium-concentration absorbing liquid flowing from the high-temperature regenerator 15 to the low-temperature regenerator 16 and a liquid from the absorber 19 to the boiling unit 14. A high-temperature heat exchanger for exchanging heat with the low-concentration absorbent flowing to the low-temperature regenerator 1 from the high-temperature regenerator 15
6 is used to cool the medium-concentration absorbing liquid, and conversely to heat the low-concentration absorbing liquid flowing from the absorber 19 to the boiler 14. Reference numeral 52 shown in FIG. 1 denotes a low-temperature heat exchanger that exchanges heat between the high-concentration absorbent flowing from the low-temperature regenerator 16 to the absorber 19 and the low-concentration absorbent flowing from the absorber 19 to the boiler 14, The high-concentration absorbent flowing from the low-temperature regenerator 16 to the absorber 19 is cooled, while the low-concentration absorbent flowing from the absorber 19 to the boiler 14 is heated.

The absorption refrigeration cycle 3 of this embodiment is provided with a heating operation means 53 for performing a heating operation in addition to the cooling operation by the above-described operation. The heating operation means 53 branches off from the middle of the middle liquid pipe 26 that guides the medium-concentration absorbent from the high-temperature regenerator 15 to the low-temperature regenerator 16, and evaporates the high-temperature absorbent into the evaporator 18 and the absorber 19. It comprises a heating pipe 54 leading to the absorption container 41 and a cooling / heating switching valve 55 (corresponding to a heating valve of the present invention) for opening and closing the heating pipe 54. The cooling / heating switching valve 55 opens during the heating operation to guide the high-temperature absorbing liquid into the evaporating / absorbing container 41 and heat the cold / hot water flowing in the evaporating heat exchanger 42 of the evaporator 18.

[Explanation of Indoor Air-Conditioning Means 4] An indoor heat exchanger 61 installed indoors, a cold / hot water circuit 6 for circulating cold / hot water
2 (corresponding to the heat medium circuit of the present invention) and a cold / hot water pump 63 (corresponding to the heat medium pump of the present invention) for circulating the heat medium in the heat medium circuit. The indoor heat exchanger 61 is a gas and liquid heat exchanger that exchanges heat between the cold and hot water that has passed through the evaporator 18 and the indoor air, and forcibly heats the cold and hot water that flows through the indoor heat exchanger 61 and the indoor air. An indoor fan 64 for exchanging and blowing out the air after the heat exchange into the room is provided.

The cold / hot water circuit 62 guides the cold / hot water passing through the evaporator 18 to the indoor heat exchanger 61 installed in the room.
A water pipe for introducing the cold and hot water that has exchanged heat with the indoor air to the evaporator 18 again. In the cold and hot water circuit 62, in addition to the indoor heat exchanger 61 and the cold and hot water pump 63, cold and hot water is stored. A cistern 65 for replenishing cold and hot water is provided in 62.
A water supply pipe 66 for supplying cold / hot water (tap water) to the inside is connected to the cistern 65. The water supply pipe 66 is provided with a water supply valve 67 that supplies and stops cold and hot water into the cistern 65. The cistern 65 is provided with a water level sensor (not shown). When the cooling water in the cistern 65 decreases, the water supply valve 67 is opened to replenish the cistern 65 with cold and hot water. Further, the cistern 65 is provided with overflow water supply means 68 for guiding the overflowed cold / hot water into a cooling water tank 78 described later.

[Description of Cooling Water Cooling Means 5] The cooling water cooling means 5 includes an evaporative cooling tower 71, a cooling water circuit 72 for circulating cooling water, and a cooling water pump for circulating cooling water in the cooling water circuit 72. 73 is provided. The cooling tower 71 includes the absorber 1
The cooling water that has passed through the condenser 9 and the condenser 17 flows downward from above, exchanges heat with the outside air while flowing to radiate heat, and partially evaporates during the flow, thereby cooling during the evaporation. A spraying unit 74 for removing the vaporization heat from the water and cooling the flowing cooling water, and spraying the cooling water upward.
And an evaporator 75 having a large surface area through which the cooling water flows, and a collector 76 for collecting the cooling water passing through the evaporator 75. In addition, the cooling tower 71 includes a cooling water fan 77 that generates an airflow in the evaporating section 75 and promotes evaporation and cooling of the cooling water in the evaporating section 75.

The cooling water circuit 72 passes the cooling water, which has passed through the absorber 19 and the condenser 17 and has increased in temperature, to the cooling tower 7.
1 and sends the cooling water cooled by the cooling tower 71 to the absorber 19 and the condenser 17 again. In the cooling water circuit 72, in addition to the cooling tower 71 and the cooling water pump 73,
A cooling water tank 78 for storing cooling water is provided. The cooling water tank 78 is provided below the cooling tower 71 and at the cistern 6
5, the cooling water passing through the cooling tower 71 is supplied, and the water overflowed by the cistern 65 is supplied. The cooling water tank 78 is provided with a water level sensor (not shown). When the cooling water in the cooling water tank 78 decreases, the water supply valve 67 is opened to overflow water from the cistern 65, and the overflowed water is supplied from the overflow water supply means 68. It is provided so as to be guided into the cooling water tank 78 and replenish the cooling water.

[Explanation of the control device 6] The control device 6 includes the refrigerant valve 39, the solution pump 47, the cold / hot water pump 63, the indoor fan 64, the cooling / heating switching valve 55, the water supply valve 67, the cooling water pump 73, and the cooling water. Electrical functional components such as fan 77,
And electric functional components of the heating means 2 (combustion fan 13, gas amount control valve 81, gas on-off valve 82, ignition device 83, etc.)
Is controlled in accordance with an operation instruction of a controller (not shown) manually set by a user and input signals of a plurality of sensors provided.

As an example of a sensor input to the control device 6, a liquid temperature sensor 85 for detecting the temperature of the low-concentration absorbent in the boiler 14, and an outdoor temperature (environmental temperature) where the absorption refrigeration cycle 3 is installed. And an outside air temperature sensor 86 (corresponding to the absorbent temperature detecting means of the present invention) for detecting the temperature of the absorbent in the absorption refrigeration cycle 3 by detecting the temperature of the absorbent. When stopping the cooling operation, the control device 6 stops the heating means 2 and, when the refrigerant valve 39 and the cooling / heating switching valve 55 are closed, the temperature of the low-concentration absorbing liquid detected by the liquid temperature sensor 85 reaches a predetermined temperature. A first dilution operation means 87 for operating the solution pump 47 until the temperature decreases to (for example, 110 ° C.) is provided. By this dilution operation, the refrigerant and the absorbing liquid in the absorption refrigeration cycle 3 circulate, and the absorption liquid having a high concentration in the absorption refrigeration cycle 3 becomes a predetermined absorption liquid temperature (for example,
° C, this temperature is equal to or lower than the dilution start temperature to be described later) to a concentration that does not cause crystallization. In other words, after the operation is stopped, a slight concentration difference is left in the absorption refrigeration cycle 3 in order to improve the rise of the cooling when the next cooling is started. Even if the installed outside air temperature decreases to the predetermined absorption liquid temperature and the temperature of the absorption liquid in the absorption refrigeration cycle 3 also decreases to the predetermined absorption liquid temperature, crystallization is prevented from occurring in the absorption refrigeration cycle 3. Things.

The control device 6 includes operating state storage means 88 for storing the last operating state of the absorption refrigeration cycle 3, that is, the last operating state of the absorption air conditioner 1. The operating state storage means 88 uses a nonvolatile memory (for example, an EEPROM) whose stored contents are not erased even when the power is turned off. Further, the controller 6 determines that while the operation of the absorption air conditioner 1 is stopped, the previous operation state stored in the operation state storage means 88 is the cooling operation, and the outside air temperature detected by the outside air temperature sensor 86 is equal to the above-mentioned predetermined absorption. When the temperature drops to a predetermined dilution start temperature (for example, 5 ° C.) or lower which is higher than the liquid temperature, the refrigerant valve 39 and the cooling / heating switching valve 55 are opened with the heating means 2 stopped, and the solution pump 47 is operated to absorb the liquid. A second dilution operation means 89 is provided for circulating the refrigerant and the absorbing liquid in the refrigerating cycle 3 for a predetermined time (for example, 2 minutes) to make the concentration of the absorbing liquid almost uniform. By this operation, crystallization does not occur in the absorption refrigeration cycle 3 even if the outside air temperature falls below the predetermined absorption liquid temperature and the absorption liquid in the absorption refrigeration cycle 3 also falls below the predetermined absorption liquid temperature.

Next, the operation of the first dilution operation means 87 will be described with reference to the flowchart of FIG. During the cooling operation, when the controller gives an instruction to stop the cooling operation, or when the controller 6 gives an instruction to stop the cooling operation for safe operation (start), the solution pump 47 and the cooling water cooling means are provided. 5 while continuing to operate the combustion fan 13 of the heating means 2.
The energization of the gas control valve 81 and the gas on-off valve 82 is stopped to stop gas combustion in the gas burner 11 (step S1).

Next, it is determined whether the temperature of the low-concentration absorbing liquid detected by the liquid temperature sensor 85 is 110 ° C. or less (step S2). If this determination is NO, the process returns to step S2. If the decision result in the step S2 is YES, the concentration of the absorbent in the absorption refrigeration cycle 3 becomes:
It is determined that the dilution is performed to a state where crystallization does not occur until the temperature of the absorption liquid drops to a predetermined value, and all the operations of the absorption air conditioner 1 are stopped (step S3).

Next, the operation of the second dilution operation means 89 will be described with reference to the flowchart of FIG. If the previous operation state stored in the operation state storage means 88 is the cooling operation (start) while the absorption air conditioner 1 is stopped, the outside air temperature detected by the outside air temperature sensor 86 becomes 5 ° C. (dilution start temperature) or less. A determination is made as to whether or not the temperature has decreased (step S1).
1). If this determination is NO, the process returns to step S11. If the determination result is YES, the refrigerant valve 3 is used to make the concentration of the absorbent in the absorption refrigeration cycle 3 uniform.
9 and the cooling / heating switching valve 55 are opened, and the solution pump 47 is operated (step S12). Next, it is determined whether two minutes have passed since the start of the dilution operation (step S13). If this determination is NO, the process returns to step S13. If the decision result in the step S13 is YES, it is determined that the concentration of the absorbing liquid has become substantially uniform, and all the operations of the absorption air conditioner 1 are stopped (step S14). After the dilution operation, the previous operation state stored in the operation state storage unit 88 is not the cooling operation but the second dilution operation. No 2 dilution operation is performed.

[Effects of the Embodiment] In the absorption type air conditioner 1 of the present embodiment, as shown in the above-mentioned operation, the first dilution operation performed when the cooling operation is stopped is performed by the absorption type air conditioner in the absorption refrigeration cycle 3. This is a dilution operation in which a slight difference in concentration is left in the liquid, and is excellent in the next startup of cooling. In addition, during the period when the cooling operation is frequently performed, such as in the summer, even if the temperature of the absorbent decreases,
Crystallization of the absorbing solution is prevented. When the cooling season is over and the outside air temperature at which the absorption refrigeration cycle 3 is installed is 5 ° C.
The second dilution operation performed when the temperature has decreased to (dilution start temperature) substantially equalizes the concentration of the absorption liquid in the absorption refrigeration cycle 3, and therefore, even if the outside air temperature is extremely reduced, such as in winter,
Crystallization of the absorbing solution can be prevented.

In this embodiment, when the concentration of the absorbing solution is made uniform by the second dilution operation, the refrigerant valve 39 and the cooling / heating switching valve 55 are opened. 15 can supply the absorbing liquid into the evaporation absorption container 41 via the heating pipe 54, and the supplied relatively high-absorbing liquid is supplied to the refrigerant supplied from the condenser 17 through the refrigerant valve 39 or the refrigerant. Mixes with low concentration absorbents. As a result, in the present embodiment, the time for equalizing the absorption liquid in the absorption refrigeration cycle 3 can be shortened to 2 minutes. Furthermore, by using a non-volatile memory for the operation state storage means 88, the previous operation state can be stored by a simple circuit.

[Modification] In the above embodiment, the second dilution operation is started by detecting the environmental temperature (outside air temperature) where the absorption refrigeration cycle is installed and estimating a decrease in the absorption liquid temperature. However, the temperature of the absorbent in the absorption refrigeration cycle may be directly detected, and the second dilution operation may be performed when the directly detected temperature of the absorbent drops to the dilution start temperature. In the above embodiment, the double-effect absorption refrigeration cycle 3 has been described as an example, but a single-effect absorption refrigeration cycle may be used, or a triple-effect or multiple-effect absorption refrigeration cycle may be used. . In addition, when the medium-concentration absorbing liquid is injected into the low-temperature regenerator, an example in which the medium-concentration absorbing liquid is injected from above the low-temperature regenerator has been described.

Although a gas burner is used as a heating source of the heating means, an oil burner or an electric heater may be used, or exhaust heat of another device (for example, an internal combustion engine) may be used. Although the example in which the heat exchanger for condensation, the heat exchanger for evaporation, and the heat exchanger for absorption are provided in a coil shape is shown, the heat exchanger of another type such as a tube and fin or a stacked heat exchanger is used. Is also good. Although an aqueous lithium bromide solution has been described as an example of the absorbing liquid, other absorbing liquids such as an aqueous ammonia solution using ammonia as a refrigerant and water as an absorbent may be used.

Although an example in which tap water is used as the heat medium and shared with the cooling water in the cooling water circuit has been described, other heat medium such as antifreeze or oil different from the cooling water in the cooling water circuit may be used. good. The numerical values shown in the above embodiments are examples used for easy understanding of the embodiments, and the present invention is not limited to the numerical values of the embodiments at all, and is suitable for the purpose of use and the scale of the apparatus. Numerical values can be appropriately adopted.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an absorption type air conditioner.

FIG. 2 is a flowchart showing an operation of a first dilution operation means.

FIG. 3 is a flowchart showing the operation of a second dilution operation means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Absorption air conditioner 2 Heating means 3 Absorption refrigeration cycle 4 Indoor air conditioning means 5 Cooling water cooling means 6 Control device 15 High temperature regenerator 16 Low temperature regenerator 17 Condenser 18 Evaporator 19 Absorber 47 Solution pump 54 Heating pipe 55 Cooling / heating Switching valve 61 Indoor heat exchanger 62 Cold and hot water circuit (heat medium circuit) 63 Cold and hot water pump (heat medium pump) 86 Outside air temperature sensor (absorbent temperature detection means) 87 First dilution operation means 88 Operating state storage means 89 Second Dilution operation means

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F25B 15/00 306

Claims (4)

(57) [Claims] A) a heating means for heating the absorbing liquid; b) a regenerator for heating the absorbing liquid with the heating means to vaporize a part of the absorbing liquid; and cooling the vaporized refrigerant generated in the regenerator. A condenser that liquefies and evaporates the liquefied refrigerant liquefied by the condenser under a low pressure; an absorber that absorbs the vaporized refrigerant evaporated by the evaporator into an absorbing liquid; An absorption refrigeration cycle having a solution pump for pumping to a regenerator; c) an indoor heat exchanger installed in a room for exchanging heat between indoor air and a heat medium; evaporating when the liquefied refrigerant evaporates in the evaporator. A heat medium circuit that guides the heat medium, which has been deprived of latent heat and cooled, to the indoor heat exchanger, and also guides the heat medium that has been heat-exchanged with the indoor air by the indoor heat exchanger to the evaporator again; Heat that circulates the heat medium Indoor air-conditioning means having a body pump; d) when stopping the cooling operation, while the heating means is stopped, operating the solution pump to circulate the refrigerant and the absorbent in the absorption refrigeration cycle; While the operation is stopped, the absorbent having a high concentration in the absorption refrigeration cycle,
A first dilution operation means for diluting to a concentration that does not crystallize at a predetermined absorption liquid temperature, e) the absorption liquid temperature detecting means for detecting the temperature of the high absorption liquid density in the shutdown of the absorption refrigeration cycle, f ) The absorbent heated by the heating means is directly
The heat medium flowing through the evaporator is guided to the evaporator,
Heating operation means for performing internal heating; and g) storing the last operation state of the absorption refrigeration cycle.
And operating state storage means that, h) the previous operating conditions to be stored in the operating state storage means
In cooling operation, when the temperature of the absorbing solution detected by the absorbing solution temperature detecting means decreases to a predetermined dilution start temperature set to be equal to or higher than the predetermined absorbing solution temperature, the solution pump is stopped with the heating means stopped. And a second dilution operation unit for circulating the refrigerant and the absorption liquid in the absorption refrigeration cycle to make the concentration of the absorption liquid substantially uniform. 2. The absorption air conditioner according to claim 1, wherein said absorption liquid temperature detection means is an outside air temperature sensor for detecting an environmental temperature in which said absorption refrigeration cycle is installed, and said second dilution operation means is: When the ambient temperature detected by the outside air temperature sensor decreases to the predetermined dilution start temperature during operation stop, it is determined that the temperature of the highly concentrated absorbent in the absorption refrigeration cycle has also decreased to the predetermined dilution start temperature. Absorption type air conditioner. 3. The absorption type air conditioner according to claim 1 , wherein the heating operation means guides the absorbing liquid heated by the heating means to the evaporator, and performs a heating operation on the heating pipe. An absorption air conditioner, comprising: a heating valve that opens therein; and wherein the second dilution operation unit opens the heating valve when the concentration of the absorbing solution is made uniform. 4. The absorption type air conditioner according to claim 1 , wherein said operation state storage means is a storage means using a nonvolatile memory.