JP3450718B2 - Absorption refrigeration equipment - 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 refrigeration system, and more particularly to an absorption refrigeration system in which piping is simplified by devising a circulation system for circulating a refrigerant liquid or an absorbent solution.

[0002]

2. Description of the Related Art In an absorption type refrigerating apparatus, an absorption refrigerating cycle is realized by supplying and circulating a refrigerant and an absorbent solution to necessary places by a pump. For example,
In the absorber that stores the absorbent solution in the storage tank, the pump function that circulates the absorbent solution in the upper part of the absorber to disperse the absorbent solution in the cooling water pipe, and the absorbent solution diluted with the refrigerant vapor (dilute solution) ) Is required to be fed to the regenerator to increase its concentration.

On the other hand, in an evaporator in which a refrigerant liquid is stored in a storage tank, a pump function is circulated in the upper part of the evaporator to disperse the refrigerant liquid in a cold water pipe, and the refrigerant liquid is evaporated little by little for the purpose of improving purity. It is required to have a pump function to extract from the vessel and feed it to the rectifier.

As described above, the absorber and the evaporator feed the absorbent solution and the refrigerant liquid, respectively, to the two circulation systems. However, providing two pumps for each of the absorber and the evaporator to circulate the absorbent solution and the refrigerant liquid is not preferable in terms of the installation space of the pump and the complicated piping.

Further, when a large number of pumps corresponding to the respective required functions are to be provided, the connecting portion of the pipe increases,
Since there is a strong risk of leakage in absorbers and evaporators with a high degree of vacuum, it is necessary to take measures against it. Therefore, in the absorption refrigeration system already proposed by Japanese Patent Application No. 9-250013, it is considered to use the discharge ports of a single pump provided in each of the absorber and the evaporator by branching.

[0006]

The absorption refrigeration system having one pump has the following problems. For example, focusing on the circulation system from the absorber, the amount of the absorbent solution sprayed to the cooling water pipe is relatively large, whereas the amount of the absorbent solution fed to the regenerator is small. Further, while the head from the storage tank of the absorbent solution to the upper part of the absorber is relatively low, the head from the absorber on the low pressure side to the regenerator on the high pressure side is relatively high. That is, for a single pump,
It is necessary to combine the functions of the pump with the large flow and small head and the functions of the pump with the small flow and large head, which are mutually opposite. Therefore, there is a problem in that it is difficult to perform optimal control for feeding an appropriate amount of the absorbent solution to each required location. This is a common problem when the refrigerant liquid is fed from the evaporator to the upper part of the evaporator and the rectifier.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide an absorption type refrigerating apparatus which can satisfy mutually opposing pumping functions with a simplified single pump.

[0008]

According to the present invention, in an absorption refrigeration system, a pump having a single suction port, a first discharge port having a large flow rate and a low pump head and a second discharge port having a small flow rate and a high pump head. Is provided in order to circulate and feed at least one of the absorbent solution in the absorber and the refrigerant liquid in the evaporator.

In the absorber, the absorbent solution in the absorber is sucked from the suction port, and the sucked absorbent solution is discharged from the first discharge port to be recirculated in the absorber. The inhaled absorbent solution was discharged from the second discharge port and fed to the regenerator.

In the evaporator, the refrigerant liquid in the evaporator is sucked from the suction port, the sucked refrigerant liquid is discharged from the first discharge port, and is recirculated in the evaporator. The sucked refrigerant liquid is discharged from the second discharge port and fed to the rectifier.

According to the above feature, the two discharge ports having different discharge characteristics are formed in a single pump. Then, the absorbent solution or the refrigerant liquid is fed and circulated for the application suited to the discharge characteristics.

Further, the present invention is characterized in that different discharge characteristics of the first discharge port and the second discharge port are set depending on a flow passage cross-sectional area and a flow passage length in the pump. According to this feature, it is possible to obtain different discharge characteristics depending on the shape of the flow path in the pump, so that it is possible to easily cope with this by setting the inner surface shape of the member forming the flow path, for example, the casing of the pump.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. FIG. 2 is a system block diagram showing a main configuration of an absorption refrigeration system according to an embodiment of the present invention. Here, an absorption cooling / heating apparatus is assumed as an embodiment of the absorption refrigeration apparatus. The evaporator 1 contains a fluoroalcohol such as trifluoroethanol (TFE) as a refrigerant, and the absorber 2 contains DMI (dimethylimidazolidinone) or a derivative thereof as a solution containing an absorbent.
The refrigerant is not limited to fluorinated alcohols as long as it has a wide non-freezing range, and the solution is not limited to the DMI derivative and can have a wide non-freezing range, and
Any absorbent having a normal pressure boiling point higher than that of TFE and capable of absorbing TFE may be used.

The evaporator 1 and the absorber 2 are fluidly connected to each other via an evaporation (refrigerant) passage (not shown),
When these spaces are kept under a low pressure environment of, for example, about 30 mmHg, the refrigerant in the evaporator 1 evaporates and enters the absorber 2 via the passage 5. A precooler 18 is provided to heat and vaporize the mist (fog-like refrigerant) remaining in the refrigerant vapor, and to lower the temperature of the TFE fed from the condenser 9. The absorbent solution in the absorber 2 absorbs the refrigerant vapor to perform the absorption refrigeration operation.

First, when the burner 7 is ignited and the solution concentration in the absorber 2 is increased by the regenerator 3 (burner, regenerator and solution concentration will be described later), the solution in the absorber 2 absorbs the refrigerant vapor. Then, the inside of the evaporator 1 is cooled by the latent heat due to the evaporation of the refrigerant. Inside the evaporator 1, a pipe line 1a through which cold water passes is provided. One end (outlet end in the figure) of the pipe 1a is connected to the # 1 opening of the first four-way valve V1, and the other end (inlet end in the figure) is connected to the # 1 opening of the second four-way valve V2.

The refrigerant is guided by the pump P1 to the spraying means 1b provided in the evaporator 1 and sprayed onto the pipe line 1a through which the cold water passes. The refrigerant takes heat of evaporation from the cold water in the pipeline 1a to become refrigerant vapor, and flows into the absorber 2 through the evaporation passage. As a result, the temperature of the cold water in the conduit 1a drops. The refrigerant in the evaporator 1 is guided to the spraying means and, as will be described later, a part thereof passes through the filter 4 and is fed to the rectifier 6 as a gas-liquid contact liquid. A flow rate control valve V5 is provided between the evaporator 1 and the filter 4. The flow rate control valve V5 is configured such that the opening degree can be switched between large and small stages, and the supply amount of bleed can be changed by this switching. It is preferable to use an aqueous solution of ethylene glycol or propylene glycol as the cold water flowing through the conduit 1a.

When the vapor of the fluoroalcohol, that is, the refrigerant vapor is absorbed by the solution in the absorber 2, the temperature of the solution rises due to the heat of absorption. The absorption capacity of the solution is higher as the temperature of the solution is lower and the solution concentration is higher. Therefore, in order to suppress the temperature rise of the solution, a pipe 2a is provided inside the absorber 2, and cooling water is passed through the pipe 2a. One end (outlet end in the figure) of the pipe line 2a passes through the inside of the condenser 9 and then the # of the first four-way valve V1 via the pump P3.
The second opening is connected to the # 2 opening of the second four-way valve V2. The same aqueous solution as the cold water is used as the cooling water passing through the pipe 2a.

The solution is guided by the pump P2 to the spraying means 2b provided in the absorber 2 and sprayed on the conduit 2a. As a result, the solution is cooled by the cooling water passing through the conduit 2a. On the other hand, since the cooling water absorbs heat, its temperature rises. When the solution in the absorber 2 absorbs the refrigerant vapor and the concentration of the absorbent decreases, the absorption capacity decreases. Therefore,
In the regenerator 3 and the rectifier 6, the refrigerant vapor is separated and generated from the absorbent solution to increase the concentration of the solution and recover the absorption capacity.

The solution, that is, the dilute solution, which is obtained by absorbing the refrigerant vapor in the absorber 2 and is diluted, is guided to the spraying means 2b, and is also fed by the pump P2 to the rectifier 6 through the pipe line 7b to the regenerator 3. It is made to flow down. The regenerator 3 has a burner 7 that heats the dilute liquid supplied from the absorber 2. The burner 7 is preferably a gas burner, but may be any other type of heating means. The solution (concentrated liquid), which is heated in the regenerator 3 and whose refrigerant vapor is extracted to increase the concentration, is returned to the absorber 2 via the pipe line 7a. An on-off valve V4 is provided on the pipeline 7a, and the concentrated liquid is sprayed on the pipeline 2a by the spraying means 2c.

When the rare liquid fed to the regenerator 3 is heated by the burner 7, refrigerant vapor is generated. This refrigerant vapor is sent to the rectifier 6, and the absorbent solution mixed therein is separated. In this way, the refrigerant vapor having a higher purity is fed to the condenser 9. The refrigerant cooled and condensed and liquefied in the condenser 9 is sent to the evaporator 1 via the precooler 18 and the expansion valve 11 and is scattered on the pipe line 1a.

Although the purity of the refrigerant supplied from the condenser 9 to the evaporator 1 is extremely high, only a slight amount of the absorbent component is mixed. It is inevitable that this absorbent component accumulates due to a long operating cycle and the purity of the refrigerant in the evaporator 1 gradually decreases. Therefore, as described above, a small part of the refrigerant is fed from the evaporator 1 to the rectifier 6 via the filter 4, and the refrigerant vapor generated from the regenerator 3 is subjected to a cycle for increasing the purity again. ing.

The high-temperature concentrated liquid in the pipe 7a coming out of the regenerator 3 came out of the absorber 2 by the heat exchanger 12 provided in the middle of the pipe connecting the absorber 2 and the rectifier 6. After being cooled by exchanging heat with the dilute liquid, it is recovered in the absorber 2. On the other hand, the diluted liquid preliminarily heated by the heat exchanger 12 is fed to the regenerator 3. Although the thermal efficiency is improved in this way, the heat of the concentrated liquid that is refluxed is further absorbed by the absorber 2 or the condenser 9
By providing a heat exchanger (not shown) for transferring to the cooling water in the pipeline 2a that has flown out of the pipe 2, the temperature of the concentrated liquid recirculated to the absorber 2 is further lowered, and the cooling water temperature is further increased. You may take the structure which can raise.

A pipe 4a is passed through a sensible heat exchanger 14 for exchanging heat between the cold water or the cooling water with the outside air.
5 is provided with a conduit 3a. One end (inlet end in the figure) of each of the pipelines 3a and 4a is # 3, 4 opening of the first four-way valve V1, and the other end (outlet end in the figure) is # 3, 4 opening of the second four-way valve V2. Respectively connected to. The indoor unit 15 is provided in a room for cooling and heating, and is provided with a fan for blowing cold air or hot air (both are common) 10 and an outlet (not shown). The sensible heat exchanger 14 is placed outdoors, and the fan 19 forcibly exchanges heat with the outside air.

The evaporator 1 is provided with a level sensor L1 for detecting the amount of refrigerant, a temperature sensor T1 for detecting the temperature of the refrigerant, and a pressure sensor PS1 for detecting the pressure inside the evaporator 1. The absorber 2 is provided with a level sensor L2 that senses the amount of the solution. The condenser 9 is provided with a level sensor L9 that senses the amount of condensed refrigerant, a temperature sensor T9 that senses the temperature of the refrigerant, and a pressure sensor PS9 that senses the pressure inside the condenser 9.

The sensible heat exchanger 14 has a temperature sensor T14 for detecting the outside air temperature, the indoor unit 15 has a temperature sensor T15 for detecting the temperature of a room to be cooled and heated, and the regenerator 3 has a temperature of the solution. Each temperature sensor T3 is provided.

During the cooling operation, the first and second four-way valves V1 and V2 are switched to positions where the # 1 and # 3 openings are in communication and the # 2 and # 4 openings are in communication. As a result, the cold water whose temperature has been lowered by spraying the refrigerant on the pipeline 1a is guided to the pipeline 3a of the indoor unit 15 to cool the room.

During the heating operation, the first and second four-way valves V1 and V2 are switched to positions where the # 1 and # 4 openings are in communication and the # 2 and # 3 openings are in communication. As a result, the warmed cooling water in the conduit 2a is guided to the conduit 3a of the indoor unit 15 to heat the room.

When the outside air temperature becomes extremely low during the heating operation, it becomes difficult to draw heat from the outside air through the sensible heat exchanger 14, and the heating capacity is lowered. In such a case,
A reflux passage 9a and an on-off valve 17 are provided to bypass between the condenser 9 and the regenerator 3 (or the rectifier 6). In this way, when it is difficult to pump up heat from the outside air, the absorption refrigeration cycle operation is stopped, the steam generated in the regenerator 3 is circulated between the steam and the condenser 9, and the heat of heating by the burner 7 is transferred to the inside of the condenser 9. In order to improve the heating capacity, the temperature of the cooling water is raised by the direct-fired operation that is efficiently conducted to the cooling water in the pipeline 2a.

Next, the pumps P1 and P2 for respectively feeding the refrigerant liquid and the absorbent solution from the evaporator 1 and the absorber 2 to desired portions will be described. Since all the pumps have the same configuration, the pump P1 will be representatively described. 3 is a front view of the pump P1, and FIG. 4 is a sectional view taken along the line AA of FIG. The pump P1 is a vortex pump (Wesco pump) , and has a motor unit M and a pump unit P. The motor unit M includes a stator 20 and a rotor (multi-pole magnet) 21, and the stator 20 is a pump P.
The rotor 21 is held by the casing 22 of No. 1 and is rotatably supported by the shaft 24 held by the cap 23 of the pump portion P via the bearing 25.

On the other hand, the pump portion P has a space surrounded by the cap 23 and the base 26, and the impeller 27 is arranged in the space. Impeller 27 is boss 29
It is rotatably supported by the shaft 24 via. A portion of the void except the portion occupied by the impeller 27, that is, a portion 28 left on the outer periphery of the impeller 27 serves as a flow path for the refrigerant liquid. A member 30 protruding from the rotor 21 is arranged to engage with the boss 29.

In operation, when alternating current is supplied to the coil of the stator 20 to generate a rotating magnetic field, the rotor 21 rotates following the rotating magnetic field. The rotation of the rotor 21 is transmitted to the impeller 27 via the member 30, and the impeller 27 rotates in the direction of arrow R. Then, the refrigerant liquid is sucked into the flow path 38 from the suction port 31, is fed in the flow path 28 in the rotation direction of the impeller 27, and is discharged from the first discharge port 32 and the second discharge port 33.

Next, the shape of the flow path 28 of the pump P1 will be described. FIG. 1 is a schematic view showing the shape of the flow path 28. The arrow R in the figure indicates the rotation direction of the impeller 27,
Arrow F indicates the flow of the refrigerant liquid. As shown in the figure, the flow path 28 is formed by the outer periphery of the impeller 27 and the portion surrounded by the cap 23 and the base 26. Channel 2
Regarding the cross-sectional area of 8, the flow passage 28a between the suction port 31 and the first discharge port 32 has the first discharge port 32 and the second discharge port 3
It is set to be larger than the flow path 28b between the first and second channels. Regarding the length, the length from the first outlet to the second outlet 33 is slightly shorter than the length from the inlet 31 to the first outlet 32.

First ejection port 32 and second ejection port 33
The discharge pressure of the refrigerant liquid discharged from each of the discharge ports is longer as the flow path 28 from each discharge port to the suction port 31 is longer, or the cross-sectional area is larger.
Is smaller, that is, the resistance of the flow path 28 is larger, the higher. In addition, the first ejection port 32 and the second ejection port 33
The discharge flow rate from is determined by the ratio of the cross-sectional areas of the flow paths 28a and 28b. Therefore, a large flow rate low pressure refrigerant is discharged from the first discharge port 32, and a small flow rate high pressure refrigerant is discharged from the second discharge port 33.

It is preferable to spray a large amount of refrigerant to the cooling water pipe 1a in the evaporator 1, but since the head is low, it is preferable to introduce the refrigerant from the first discharge port 32 to the spraying means 1b. On the other hand, the amount of the refrigerant to be fed to the rectifier 6 depends on the cooling water pipeline 1a.
Less than the amount sprayed on the
Moreover, since the rectifier 6 has a higher pressure than the evaporator 1, the second
Good that to guide the refrigerant from the discharge port 3 3 to rectifier 6.

Although the pump P1 connected to the evaporator 1 has been described above, the pump P2 connected to the absorber 2 has the same structure. Therefore, regarding the pump P2, a pipe line connected to the spraying means 2c is connected to the discharge port from which a large flow rate low pressure (low head) is obtained, and the discharge port from which a small flow rate high pressure (high head) is obtained, It is advisable to connect the line 7b that leads the solution to the regenerator 3.

As described above, according to the absorption type cooling and heating apparatus of this embodiment, the single pumps respectively connected to the evaporator 1 and the absorber 2 perform two types of pump functions having different flow rates and pressures. You can

[0037]

According to the present invention, two discharge characteristics different from each other can be obtained with a single pump, so that the installation space of the pump can be narrowed, piping can be simplified, and the number of joints of piping can be reduced. It is possible to reduce the leak factor. Further, in particular, according to the invention of claim 3, the discharge characteristic can be easily set by the shape of the member forming the flow passage, for example, the pump casing.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a shape of a pump channel of a cooling and heating apparatus according to an embodiment of the present invention.

FIG. 2 is a system block diagram showing the configuration of the cooling and heating device according to the embodiment of the present invention.

FIG. 3 is a front external view of the pump.

FIG. 4 is a side sectional view of a main part of the pump.

[Explanation of symbols]

1 ... Evaporator, 1a ... Cold water pipeline, 2 ... Absorber, 2
a ... Cooling water conduit 3 ... Regenerator, 4 ... Filter, 6
... Fractionator, 7 ... Burner, 9 ... Condenser, 9a ... Circular flow path 10 ... Fan, 14 ... Sensible heat exchanger, 15 ... Indoor unit, 20 ... Comparison section, 21 ... Reference value setting section, 27 ...
Impeller, 28 ... Flow path, 31 ... Suction port, 32 ... First discharge port, 33 ... Second discharge port

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F25B 15/00 301 F25B 15/00 F25B 15/00 306 F25B 41/00

Claims (4)

(57) [Claims] 1. An evaporator containing a refrigerant liquid, an absorber containing an absorbent solution containing an absorbent that absorbs the refrigerant vapor generated in the evaporator to generate heat of absorption, and the absorbent solution. In an absorption refrigeration system having a regenerator that heats and extracts refrigerant vapor from the absorbent solution, and a condenser that condenses the refrigerant vapor extracted by the regenerator and supplies it to the evaporator, A pump having a suction port, a first discharge port having a large flow rate and low head and a second discharge port having a small flow rate and high head is provided, and the absorbent solution in the absorber is sucked and sucked from the suction port. The absorbent solution is discharged from the first discharge port and recirculated in the absorber, and the sucked absorbent solution is discharged from the second discharge port and fed to the regenerator. An absorption type refrigeration system characterized by the above. 2. An evaporator containing a refrigerant liquid, an absorber containing an absorbent solution containing an absorbent that absorbs the refrigerant vapor generated in the evaporator to generate heat of absorption, and the absorbent solution. A regenerator that heats to extract the refrigerant vapor from the absorbent solution, a rectifier that concentrates the refrigerant vapor extracted by the regenerator, and a vaporizer that condenses the refrigerant vapor concentrated in the rectifier. In an absorption refrigeration system having a condenser for supplying to a vessel, a suction port is provided, and a pump having a first discharge port with a large flow rate low head and a second discharge port with a small flow rate high head, The refrigerant liquid in the evaporator is sucked from the suction port, the sucked refrigerant liquid is discharged from the first discharge port to be recirculated into the evaporator, and the sucked refrigerant liquid is sucked into the second refrigerant liquid.
The absorption type refrigerating apparatus, which is configured to be discharged from the discharge port of and to be fed to the rectifier. 3. The discharge characteristics of the first discharge port and the second discharge port that are different from each other are set according to a flow channel cross-sectional area and a flow channel length in the pump. Item 2. The absorption type refrigerating apparatus according to item 2. 4. The pump has an impeller arranged in the center thereof, and forms a flow path along the outer circumference of the impeller, and on the flow path, the first discharge port and the second discharge port are arranged in order from the suction port. The absorption type refrigerating apparatus according to any one of claims 1 to 3, wherein a discharge port is arranged.