JP3445941B2 - Multi-stage evaporative absorption type absorption chiller / heater and large temperature difference air conditioning system equipped with the same - 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 chiller-heater and a large temperature difference air-conditioning system using the same, and more particularly to a multi-stage evaporative absorption-type absorption chiller-heater suitable for building air-conditioning and district heating and cooling systems. It relates to a large temperature difference air conditioning system used.

[0002]

2. Description of the Related Art Absorption refrigerators are widely used as heat sources for building air conditioning and district heating / cooling systems because they do not use CFC-based refrigerants and consume little electricity. The absorption chiller / heater having a heating function is widely used as a heat source unit for air conditioning. To further improve the efficiency of this absorption refrigerator and absorption chiller-heater,
There is a so-called multi-stage evaporative absorption-type absorption chiller-heater equipped with a plurality of evaporators and absorbers, one example of which is JP-A-2-7.
It is described in Japanese Patent No. 8866. In the storage refrigerator described in this publication, an evaporator, an absorber, a condenser and a regenerator are each divided into two parts, a first element and a second element. Then, cold water is passed through the second evaporator having the highest temperature and the first evaporator in this order.

In a two-stage evaporative absorption type absorption refrigerator, the pressure difference between the upper heat exchanger side and the lower heat exchanger side is properly maintained, and the liquid is evenly dropped into the heat transfer tubes of the lower heat exchanger to achieve the capability. Patent Document 9: Improvement of partition wall and liquid sealing tray for improving
No. 14792.

By the way, in an air conditioning system using an absorption chiller-heater, the maximum temperature difference of the chilled water circulating between the chiller-heater and the air conditioning load system is made larger than the conventional 5K to 5.5K, and the chilled water circulation amount is reduced. There is a large temperature difference air conditioning system. An example of this large temperature difference air conditioning system is "industrial machinery".
October 1997, pp. 32-35, especially Table 1
It is described in. This large-temperature-difference air-conditioning system has the advantage that it can reduce the transport power of chilled water and downsize the piping size, and that it can be used for heating and cooling without changing the chilled water pump and piping size when using the existing air-conditioning system. It has the advantage that the capacity can be increased.

[0005]

However, in the absorption refrigerating machine of the multi-stage evaporative absorption type disclosed in Japanese Patent Application Laid-Open No. 2-78866, the first evaporator having a low cold water temperature is connected to the condenser 4 to the first evaporator.
Since the refrigerant liquid of about 0 ° C. flows in, self-evaporation occurs and the pressure in the evaporator rises. As a result, the cooling of the cold water becomes insufficient, especially in the first evaporator where the evaporation temperature and pressure are low. In addition, fine mist is generated due to self-evaporation,
Since a part of the refrigerant flows into the absorber along with the flow of the refrigerant vapor from the evaporator to the absorber, there is a risk of producing ineffective refrigerant that does not contribute to the refrigerating capacity.

Further, the structure described in Japanese Patent Laid-Open No. 9-14792 can improve the performance, but has a complicated structure. And, in the one described in this publication, although the differential pressure between the pressure on the upper heat exchanger side and the pressure on the lower heat exchanger side can be appropriately maintained, the refrigerant is uniformly dropped onto the heat transfer tube on the lower heat exchanger side. The proper head for making it do not consider.

On the other hand, the one described in the October 1997 issue of "Industrial Machinery" prevents the pressure of the condenser from rising even if the outlet temperature of the cooling water is raised so that the temperature of the cooling water and the temperature of the cooling water are increased. This has the advantage that the temperature difference is used and, as a result, the transport power can be reduced. However, since the evaporator is configured with a single space and operated under uniform pressure, the difference between the evaporation temperature and the cold water temperature in the cold water low temperature part becomes small,
The heat transfer area is not always fully utilized.

The present invention has been made in view of the above-mentioned problems in the prior art, and its object is to evenly distribute the refrigerant to the lower evaporative absorber in a vertically divided multi-stage evaporative absorption-type absorption chiller-heater. It is to drip. Another object of the present invention is to provide a multistage evaporative absorption type absorption chiller / heater,
The purpose is to simplify the structure and reduce the cost. Still another object of the present invention is a multi-stage evaporative absorption type absorption chiller / heater,
It is to improve reliability.

Another object of the present invention is to provide a large temperature difference air conditioning system including a multi-stage evaporative absorption type absorption chiller / heater.
Even when the temperature difference of cold water is large, it is to suppress the deterioration of the performance of the evaporator. Furthermore, it aims at improving energy efficiency in a large temperature difference air conditioning system.

[0010]

The first feature of the present invention for achieving the above object is to provide an evaporator and an absorber, which are vertically formed in multiple stages by partition walls, a condenser, and a regenerator. In a multi-stage evaporative absorption-type absorption chiller-heater provided with, the multi-stage evaporator and the multi-stage absorber each form a pair of an evaporator and an absorber by the partition wall, and a refrigerant re-distributor that stores a refrigerant in this partition wall. And the depth of this refrigerant re-distributor is 10-
It is 100 mm.

Preferably, the liquid refrigerant is led from the condenser to the highest pressure stage among the evaporator stages formed in multiple stages, and the upper part is passed through a large number of refrigerant dropping holes provided at the bottom of the refrigerant re-distributor. The refrigerant that has remained in the liquid state in the upper evaporator stage is guided from the evaporator stage formed in (1) to the evaporator stage formed in the lower part.

[0012] Preferably, the refrigerant is introduced from the condenser to the evaporator stage into which the cold water flowing back from the air conditioning load system first flows in the evaporator formed in multiple stages; The refrigerant is introduced from the condenser to the evaporator stage which is paired with the absorber stage to which the solution circulation pump for sending the diluted solution to the regenerator is connected.

A second feature of the present invention for achieving the above object is a multi-stage evaporative absorption type equipped with an evaporator and an absorber which are vertically formed in multiple stages by partition walls, a condenser, and a regenerator. In the absorption chiller-heater, the multi-stage evaporator and the multi-stage absorber each form a pair of an evaporator and an absorber by the partition wall, and the partition wall is provided with the non-evaporated refrigerant in the evaporator above the partition wall. A refrigerant re-distributor for accommodating and a solution re-distributor for accommodating the solution in the absorber above the partition wall are formed, and the depth of the refrigerant re-distributor and the solution re-distributor is 10 to 100 m.
m.

And, preferably, the absorber of each stage formed in multiple stages is a falling film type absorber stage; the refrigerant re-distributor is a box-shaped recess formed in the partition wall, A large number of liquid drip holes are formed on the bottom surface corresponding to a plurality of heat transfer tube positions of the evaporator stage located below the refrigerant re-distributor; the solution re-distributor is box-shaped formed on a partition wall. And a large number of liquid drip holes are formed on the bottom surface of the dimple corresponding to the positions of the plurality of heat transfer tubes of the absorber stage located below the solution re-distributor; The absorber stage, which is paired with the evaporator through which the fluid to be cooled last circulates, is the absorber stage to which the solution refluxed from the regenerator is first introduced, and is introduced to this absorber stage. A solution cooling heat exchanger for exchanging heat between the solution and the cooling water is provided.

The third feature for achieving the above object is as follows.
A container containing an evaporator and an absorber is divided into a plurality of spaces each including a part of the evaporator and a part of the absorber to form a plurality of evaporators and absorbers, and each of the above-mentioned each during operation. In a multi-stage evaporative absorption-type absorption chiller-heater configured so that spaces operate at different pressures, cooling water is first passed through a part of the plurality of absorbers, and then once through a condenser. Further, the cooling water flow path is configured so as to sequentially pass water to the remaining portions of the plurality of absorbers.

The fourth feature of the present invention for achieving the above object is that the temperature difference between the going temperature and the returning temperature of the cold water that reciprocates between the heat source system and the load system is larger than 5K in the rated operating condition. A temperature-difference air-conditioning system, comprising a multi-stage evaporative absorption-type water cooler having an evaporator and an absorber vertically formed by a partition wall in multiple stages, a condenser, and a regenerator. In the machine, the multi-stage evaporator and the multi-stage absorber each form a pair of evaporator and absorber by the partition wall, and a refrigerant re-distributor for accommodating a refrigerant is formed in the partition wall. The depth is 10 to 100 mm.

The fifth feature of the present invention for achieving the above object is that the temperature difference between the going temperature and the returning temperature of the cold water that reciprocates between the heat source system and the load system is larger than 5K in the rated operating condition. A temperature difference air-conditioning system, comprising a multi-stage evaporative absorption-type absorption chiller / heater having an evaporator and an absorber formed in multiple stages in the vertical direction by partition walls, a condenser, and a regenerator, and the multi-stage evaporation The reactor and the multi-stage absorber form a pair of an evaporator and an absorber by the partition, respectively, and a refrigerant re-distributor for accommodating the refrigerant that has not evaporated in the evaporator above the partition and a partition of this partition. A solution re-distributor for containing the solution in the upper absorber is formed, and the depths of the refrigerant re-distributor and the solution re-distributor are 10 to 100 mm.

The sixth feature of the present invention for achieving the above object is that the temperature difference between the going temperature and the returning temperature of the cold water that reciprocates between the heat source system and the load system is larger than 5K in the rated operating condition. In a temperature difference air conditioning system, an evaporator and an absorber are vertically formed in multiple stages by partition walls, a condenser, and a regenerator, and the multi-stage evaporator and the multi-stage absorber are respectively formed by the partition walls. And an absorption chiller-heater having a pair of absorbers are used as a heat source machine of the heat source machine system.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are diagrams according to a first embodiment of the present invention. In these figures,
The multi-stage evaporative absorption type absorption chiller / heater is of a two-stage evaporative absorption type, but the number of stages is not limited thereto. FIG. 1 is a schematic diagram of a two-stage evaporative absorption type absorption chiller-heater. The two-stage evaporative absorption type absorption chiller-heater includes a high temperature regenerator 1, a low temperature regenerator 2,
The condenser 3, the evaporator 4, the absorber 5, the low temperature heat exchanger 6, the high temperature heat exchanger 7, and the pipes connecting them, and the refrigerant pump 41, the dilute solution pump 51, and the concentrated solution pump 61 are provided. ing.

The evaporator 4 and the absorber 5 each have a first
It is divided into two stages, an evaporator 4a and a second evaporator 4b, and a first absorber 5a and a second absorber 5b. The portions of the first evaporator 4a and the first absorber 5a are the same as the second evaporator 4b and the second absorber 4a.
It is divided by the part b and the partition wall 45. Further, to the partition wall 45, a refrigerant re-distributor 46 for redistributing the refrigerant liquid flowing down on the evaporation heat transfer tube 44a of the first evaporator onto the evaporation heat transfer tube 44b in the second evaporator, and the first absorber A solution re-distributor 56 that redistributes the solution flowing down on the absorption heat transfer tube 54a onto the absorption heat transfer tube 54b in the second absorber is provided.

The operation of the multistage evaporative absorption type absorption chiller-heater configured as described above will be described below. The diluted solution is sent from the absorber 5 to the high temperature regenerator 1 by the diluted solution pump 51 via the low temperature heat exchanger 6 and the high temperature heat exchanger 7. A heating means such as a burner (not shown) attached to the high temperature regenerator 1 heats and concentrates this dilute solution to form a concentrated solution. This concentrated solution exchanges heat with the dilute solution sent from the absorber 5 in the high temperature heat exchanger 7, and then merges with the concentrated solution heated and concentrated in the low temperature regenerator 2 after leaving the high temperature heat exchanger 7. . On the other hand, the high-temperature refrigerant vapor generated when the dilute solution is heated and concentrated is guided to the low-temperature regenerator 2 and serves as a heating source for the solution in the low-temperature regenerator 2 described later.

Like the high temperature regenerator 1, the dilute solution is sent to the low temperature regenerator 2 from the absorber 5 by the dilute solution pump 51 through the low temperature heat exchanger 6. This dilute solution is used as a high temperature regenerator 1
The high-temperature refrigerant vapor generated in step 1 is heated and concentrated to form a concentrated solution. The solution flowing out from the low temperature regenerator 2 and concentrated is combined with the concentrated solution heated and concentrated in the high temperature regenerator 1 and cooled in the high temperature heat exchanger 7. The combined concentrated solution was used as a low temperature heat exchanger 6
After the heat is exchanged with the dilute solution to lower the temperature, the solution is introduced to the suction side of the concentrated solution pump 61. On the other hand, the refrigerant vapor generated when the dilute solution is heated and concentrated is condensed in the condenser 3 connected to the low temperature regenerator 2. The refrigerant vapor generated in the high temperature regenerator 1 and guided to the low temperature regenerator 2 flows into the condenser 3 after heating and condensing the solution in the low temperature regenerator 2.

In the condenser 3, the refrigerant vapor generated in the low temperature regenerator 2 is cooled by the cooling water and condensed. Further, the refrigerant liquid generated in the high temperature regenerator 1 and condensed in the low temperature regenerator 2 joins with this refrigerant liquid. The combined refrigerant liquid is guided to the evaporator 4 by the refrigerant pipe 31.

In the evaporator 4, the refrigerant liquid flowing from the condenser 3 is guided to the second evaporator 4b. At this time, the temperature of the refrigerant liquid becomes about 40 ° C. which is the condensation temperature in the condenser 3. The inflowing refrigerant liquid is in a superheated state with respect to the evaporation temperature in the second evaporator 4b, so that it partially self-evaporates and the rest remains in the bottom.

Since the second evaporator 4b is on the upstream (high temperature) side of the flow of cold water, the cold water outlet temperature of the second evaporator is approximately the intermediate temperature of the entire cold / hot water machine. Assuming that the temperature difference of cold water is 5 K (12 ° C. → 7 ° C.), the temperature difference is about 9.5 ° C. Therefore, if the approach temperature to the evaporation temperature is 3K, the evaporation temperature in the second evaporator 4b will be about 6.5 ° C. From this, it can be seen that the refrigerant liquid flowing from the condenser 3 is in an overheated state.

The refrigerant liquid accumulated at the bottom of the evaporator 4 is
On the heat transfer tube group 44b of the evaporator 4b, the refrigerant liquid merges with the refrigerant liquid that has not completely evaporated, and is guided by the refrigerant pump 41 through the refrigerant discharge pipe 42 to the refrigerant distribution device 43 provided in the first evaporator 4a. Get burned.

In the first evaporator 4a, the refrigerant liquid is supplied from the refrigerant distributor 43 to the surface of the evaporation heat transfer tube 44a. As a result, a falling liquid film is formed outside the pipe, and the refrigerant liquid takes heat from the cold water flowing inside the pipe to evaporate. The refrigerant vapor evaporated outside the pipe is absorbed by the first absorber 5a, and the refrigerant that has not been completely evaporated and flows down to the refrigerant re-distributor 46 installed in the partition wall 45. At this time, the refrigerant that has moved in the process of flowing down the heat transfer tube group or the evaporator that is scattered from the tube group on the inner wall of the evaporator with the heat transfer tube fixed or the heat transfer tube support plate provided in the middle of the tube axis direction The refrigerant that adhered to the inner wall of the and flowed down without evaporating,
It flows down to the refrigerant re-distributor 46.

In the second evaporator 4b, the refrigerant is supplied from the refrigerant re-distributor 46 to the surface of the evaporative heat transfer tube 44b and evaporates outside the evaporative heat transfer tube 44b like the first evaporator. The evaporated refrigerant vapor is absorbed by the second absorber 5b. The refrigerant that has flowed down without being evaporated is sent again into the first evaporator together with the refrigerant that has flowed in from the condenser 3. The cold water is cooled by the first evaporator after being cooled by the second evaporator, and is guided to the cooling load system. Therefore, the temperature of the cold water flowing in the heat transfer tube is higher in the second evaporator 4b on the upstream side. The evaporation temperature of the refrigerant outside the tube is also higher in the second evaporator 4b. That is,
The second evaporator 4b operates at a higher pressure than the first evaporator 4a. The cold water whose temperature has risen after passing through the cooling load system is recirculated to the second evaporator 4b again.

The concentrated solution whose temperature has been lowered by exchanging heat with the dilute solution in the low-temperature heat exchanger 6 is first introduced into the first absorber 5a after being pressurized by the concentrated solution pump 61, and then absorbed from the solution distributor 53. It is supplied to the surface of the heat pipe 54a. Absorption heat transfer tube 5
On the surface of 4a, the refrigerant vapor evaporated in the first evaporator 4a is absorbed by the falling liquid film of the solution. The absorbed heat generated at this time is removed by the cooling water flowing in the heat transfer tube. Therefore, the absorption capacity of the solution is maintained, which in turn promotes the absorption of the refrigerant vapor.

The solution which has absorbed the refrigerant vapor in the first absorber 5a flows down to the solution re-distributor 56 provided below the absorption heat transfer tube 54a. The solution re-distributor 56 is provided on the partition wall 45 similarly to the refrigerant re-distributor 46. The solution flowing down to the solution re-distributor 56 and the refrigerant flowing down to the refrigerant re-distributor 46 are separately provided so as not to be mixed.

On the inner wall of the absorber 5 for fixing the heat transfer tubes 54a or on the heat transfer tube support plate provided midway in the tube axial direction, the solution moved in the process of flowing down on the heat transfer tube group or scattered from the tube group. The solution that has flowed down after adhering to the inner wall of the absorber 5 also flows down to the solution redistribution device 56. These solutions flow down over the heat transfer tube group and join again with the solution that has absorbed the refrigerant.

In the second absorber 5b, the solution is supplied from the solution redistribution device 56 to the surface of the absorption heat transfer tube 54b. This solution is the same as in the case of the first absorber 5a.
A falling liquid film is formed on the outside of the pipe to absorb the refrigerant vapor evaporated in the second evaporator 4b. The absorption heat generated at this time is also the first
Like the absorber, it is removed by the cooling water flowing in the heat transfer tube. Thereby, the absorption capacity of the solution is maintained and the absorption of the refrigerant vapor is promoted. The solution that has absorbed the refrigerant vapor is
With the dilute solution pump 51 attached to the bottom of the absorber 5,
It exchanges heat with the concentrated solution which is sent to the low temperature heat exchanger 6 and flows into the absorber. Then, a part is sent to the high temperature regenerator 1 through the high temperature heat exchanger 7, and the rest is sent to the low temperature regenerator 2.

The cooling water is sent from a cooling means such as a cooling tower (not shown) into the absorption heat transfer tube 54b of the second absorber 5b to cool the solution. After that, the solution is guided to the first absorber 5a and similarly cooled. Further, the refrigerant vapor that is guided to the condenser 3 and generated in the low temperature regenerator 2 is cooled and condensed, and is returned to the cooling means.

In the absorption chiller-heater, non-condensable gas may be generated due to the reaction of the corrosion inhibitor. This non-condensed gas tends to stay in the absorber having the lowest pressure in the water heater. When the non-condensed gas stays in the absorber, it hinders the absorption of the refrigerant vapor, resulting in a decrease in the performance of the chiller / heater. Therefore, it is necessary to quickly discharge the non-condensable gas to the outside of the machine to prevent the performance from deteriorating. According to this embodiment, since the non-condensable gas discharging means in the hot and cold water machine is provided, this problem can be solved. The details will be described below.

FIG. 2 is a system diagram of the noncondensable gas discharging mechanism. The non-condensable gas staying in the absorber 5 is sent to the high temperature regenerator 1 and the low temperature regenerator 2 along with the solution sucked by the dilute solution pump 51, and then collected in the condenser 3. The collected non-condensed gas is sucked by the extraction ejector 81 via the extraction suction pipe 80. A part of the solution discharged from the dilute solution pump 51 is guided through the ejector drive pipe 82 and serves as a drive source for the extraction ejector 81. The non-condensed gas sucked from the condenser 3 by the extraction ejector 81 is guided to the gas-liquid separator 84 through the extraction ejector discharge pipe 83 together with the solution that has driven the extraction ejector 81. The gas-liquid separated solution is introduced into the second absorber 5b, while
The non-condensable gas collects in the extraction tank 85.

A part of the non-condensable gas collected in the condenser 3 is
It moves to the evaporator with the refrigerant liquid, and moves from the second evaporator 4b to which the refrigerant pipe 31 is connected to the second absorber 5b together with the flow of the refrigerant vapor. Since the dilute solution pump 51 is connected to the second absorber 5b, the non-condensed gas collects in the condenser 3 again via the regenerators 1 and 2.

Next, details of the multistage evaporative absorber used in this embodiment will be described with reference to FIGS. 3 and 4. The evaporator 4 and the absorber 5 have a plurality of partition walls 45, and in this embodiment, two partition walls are provided.
It is divided into columns. In this partition, the refrigerant re-distributor 46,
An overflow prevention plate 48 is provided to prevent the refrigerant from flowing into the solution re-distributor 47 and the absorber 4 and the solution from flowing into the evaporator. FIG. 3 shows a perspective view of the partition wall 45.

The refrigerant re-distributor 46 is the evaporator 4 of the partition wall 45.
Is formed as a box-shaped recess in a portion corresponding to. A large number of refrigerant dropping holes 47 form a plurality of rows along the heat transfer tube axial direction. Similarly, the solution re-distributor 56 is formed as a box-shaped recess in a portion of the partition wall 45 corresponding to the absorber, and a large number of solution dropping holes 57 form a plurality of rows along the axial direction of the heat transfer tube.

In FIG. 4, each row of the refrigerant dripping holes 47 provided in the refrigerant re-distributor 46 and the second evaporator 4b below the rows.
The positional relationship of each row of the evaporation heat transfer tubes 44b in the inside is shown. The refrigerant dropping holes 47 are provided in the same number of rows as the number of rows of the evaporation heat transfer tubes 44b. The central axis of each row of the refrigerant dropping holes 47 is located directly above the central axis of each row of the evaporation heat transfer tubes 44b.
The depth of the refrigerant re-distributor 46 is H. In this embodiment,
This depth H is 50 mm.

As described above, in the present embodiment, in the absorption chiller-heater having a plurality of evaporative absorbers each consisting of a pair of an evaporator and an absorber, the refrigerant flowing from the condenser to the evaporator is cooled by the air conditioning load. The second inflow of cold water refluxing from the system first
It leads to a second evaporative absorber including the evaporator 4b. Thereby, the refrigerant is allowed to self-evaporate in the second evaporative absorber, and the pressure of the refrigerant vapor in the first evaporator 4a for cooling the cold water to a low temperature can be kept low. Then, the evaporation temperature in the first evaporator 4a can be kept low, the outlet temperature of the cold water can be stabilized at a low temperature, and the difference between the evaporation temperature and the cold water can be secured. Thereby, the heat transfer area can be reduced and the evaporator can be downsized.

By the way, in this embodiment, the refrigerant in the condenser is led to the second evaporator which operates at the highest pressure among the plurality of evaporators. The ratio of the amount of self-evaporation with respect to the total flow rate of the refrigerant flowing from the condenser varies depending on the pressure in the evaporator that flows in. Table 1 shows a comparison of the cold water outlet temperature of the first evaporator and the second evaporator, the evaporation temperature, and the self-evaporation rate of the refrigerant flowing from the condenser corresponding to this evaporation temperature.

[0042]

[Table 1]

Here, as for the second evaporator, in addition to the standard temperature difference of 5K for cold water, the temperature difference of 8K for cold water is also shown assuming a large temperature difference air conditioning system. . In Table 1, the cold water outlet temperature of the second evaporator is the median value of the cold water inlet temperature and the cold water outlet temperature of the entire cold / hot water machine. Further, the evaporation temperatures were all set to be 3K as the approach temperature from the cold water outlet temperature. The refrigerant self-evaporation rate was obtained as an evaporation amount when a part of the refrigerant flowing from the condenser was evaporated and was cooled by latent heat until it became equal to the evaporation temperature.

From Table 1 it can be seen that the refrigerant self-evaporation rate is lower for evaporators with higher evaporation temperatures and therefore higher pressures. The self-evaporation of the refrigerant not only hinders maintaining a low pressure inside the evaporator, but also induces the generation of a refrigerant mist. A part of this refrigerant mist is carried to the absorber by the flow of the refrigerant vapor from the evaporator to the absorber as an ineffective refrigerant that does not contribute to the cooling capacity, which is one of the causes for lowering the performance of the chiller-heater.

On the other hand, in the present embodiment, the refrigerant from the condenser is guided to the second evaporator which operates at a higher evaporation temperature and higher evaporation pressure than the first evaporator, so that the self-evaporation is accompanied. There is little generation of refrigerant mist. Thereby, it can be reduced that the refrigerant mist becomes an ineffective refrigerant and the performance is deteriorated.

Further, according to this embodiment, the refrigerant pipe 31 for guiding the refrigerant from the condenser 3 to the evaporator 4 is connected to the diluted solution pump 51.
Second evaporator 4 communicating with a second absorber 5b connected to
Since it is connected to b, the non-condensable gas flowing from the condenser to the evaporator 4 along with the refrigerant liquid can be quickly removed from the absorber 5.

By the way, in the evaporator of the absorption chiller-heater, it is general to pass cold water from the lower heat transfer pipe toward the upper part so that the air in the cold water flow path can be easily removed. Also in this embodiment, the second evaporator into which the refrigerant flows from the condenser 3 is at the lowest stage. Therefore, the first evaporator 4a in the upper stage requires a separate means for sending the refrigerant. Therefore, the containers forming the evaporator 4 and the absorber 5 are
A portion composed of the evaporator 4a and the first absorber 5a, and a second
It is divided in the vertical direction into a portion composed of the evaporator 4b and the second absorber 5b. At the same time, the refrigerant pump 41 is provided at the bottom of the second evaporator 4b at the bottom.

In the refrigerant introduced from the condenser to the evaporator,
Most of the refrigerant liquid that has flowed to the bottom without self-evaporating is supplied from the refrigerant pump onto the heat transfer tube group of the first evaporator.
The refrigerant that has flowed down without evaporating in the heat transfer tube group is supplied to the heat transfer tube group of the second evaporator by gravity.

Further, since the absorber is also divided in the vertical direction like the evaporator, only one dilute solution pump is installed at the bottom of the second absorber at the bottom. Therefore,
In this embodiment, the refrigerant can be supplied to each of the two evaporation absorbers, although the refrigerant supply portion to the evaporator is provided in the lower portion. This can reduce the number of refrigerant pumps and dilute solution pumps.

Further, since the refrigerant re-distributor is provided on the partition wall as a box-shaped recess, the refrigerant and liquid droplets that move down on the vertical surfaces such as the tube plate, the support plate of the heat transfer tube and the inner wall of the evaporator, and the liquid droplets. The refrigerant captured by the eliminator can be collected in this refrigerant re-distributor. Then, the refrigerant flowing down on the evaporation heat transfer tube group can also be collected in this refrigerant re-distributor. The refrigerant collected in the refrigerant re-distributor is supplied again to the surface of the heat transfer tube in the second evaporator through the hole formed in the bottom of the refrigerant re-distributor. As a result, in the entire evaporator, even in the second evaporator 4b located at the lower part, the only factor that reduces the flow rate of the refrigerant flowing down on the heat transfer tube group is evaporation of the refrigerant itself. Therefore, it is possible to suppress a decrease in the wetting area of the surface of the heat transfer tube, that is, the gas-liquid interface, and the accompanying decrease in heat transfer performance.

Similarly, in the absorber 5 as well, since the solution re-distributor 56 is provided in the partition wall 45, the absorption plate 5a, the support plate of the heat transfer pipe, the inner wall of the absorber 5 and the like are vertically arranged from the surface of the absorption heat transfer pipe 54a. The solution that moves to the surface and flows down, or the solution that becomes droplets and is captured by the eliminator 50 is guided to the solution redistributor 56 in the first absorber 5a. The solution introduced to the solution re-distributor is supplied again to the surface of the heat transfer tube 54b in the second absorber 5b together with the refrigerant flowing down on the absorption heat transfer tube group. Therefore, even in the second absorber 5b located in the lower part of the entire absorber 5, the flow rate of the solution flowing down on the absorption heat transfer tube group does not decrease, and accordingly, the heat transfer performance does not decrease.

Further, in the first absorber, the solution that has moved to and flowed down on the vertical surface such as the tube plate, the support plate of the heat transfer tube, and the inner wall of the absorber 5 and droplets are captured by the eliminator 50. Since the solution is not cooled with cooling water, the absorption rate of the refrigerant vapor is low. Therefore, the concentration is higher than that of the solution flowing down while absorbing the refrigerant vapor on the heat transfer tube group. Therefore, in the present embodiment, since the solution having a high concentration is combined with the solution flowing down from the heat transfer tube group,
The concentration of the solution supplied to the absorber 5b is increased, and the 5b absorption capacity of the second absorber is improved.

Further, according to this embodiment, the concentrated solution deviated from the heat transfer tube group of the first absorber 5a is directly absorbed by the absorber 5
Can be prevented from flowing into the lower part of. Therefore, the concentration of the diluted solution sent to each regenerator by the diluted solution pump 51 decreases, and the concentration difference from the concentrated solution increases. As a result, the solution circulation amount is small, and the pipe size and the volumes of the dilute solution pump and the concentrated solution pump can be reduced.

In the above embodiment, the depths of the refrigerant re-distributor 46 and the solution re-distributor 56 are set to 50 mm. As a result, it is possible to secure a liquid head for reliably supplying the refrigerant and the solution onto the heat transfer tube group of the second evaporator 4b and the second absorber 5b, which are located directly below the dropping holes of the re-distributor. . The reason for this will be further described with reference to FIG.

FIG. 5 shows the partition wall 45 shown in FIGS. 3 and 4.
The refrigerant re-distributor 46 and the solution re-distributor 56.
5 is a graph showing a result obtained experimentally by the present inventors about an appropriate depth of. In the experiment, a tray-shaped liquid distributor having a box-shaped depression was used, and water was used as a test liquid. Then, the water depth in the tray and the dropping state from each dropping hole were observed while changing the flow rate of water. The number of drip holes is 8
There are three types, namely, 12 pieces, and 16 pieces.

The horizontal axis of FIG. 5 represents the flow rate of water supplied to the tray, and the vertical axis represents the water depth in the tray and the proper dropping rate. Here, the proper dropping rate is defined as a value obtained by dividing the number of dropping holes in which the liquid under test is directly supplied from the dropping holes by the total number of dropping holes. Therefore, in the state where the liquid is properly distributed, the appropriate dropping rate is 100%. This state is almost realized when the water depth of the tray exceeds about 10 mm. That is, it was found that a head of at least 10 mm was required to accurately supply the liquid from the dropping hole to the heat transfer tube installed directly thereunder.

On the other hand, the amount of refrigerant in the evaporator and the amount of solution in the absorber have appropriate values. Further, as the tray becomes deeper, the size of the container in which the evaporator and the absorber are integrally formed increases. Taking these into consideration, the upper limit of the tray depth is 10
Set to 0 mm.

In this embodiment, since both the refrigerant re-distributor 46 and the solution re-distributor 56 have a depth of 50 mm, it is possible to secure a head of 10 mm or more inside the box-shaped recess. Then, the refrigerant and the solution can be accurately redistributed onto the heat transfer tube group, and the heat exchange with the cold water and the cooling water flowing in the heat transfer tube can be maintained well.

Next, another embodiment of the present invention will be described with reference to FIG. This embodiment is different from the above-mentioned embodiments in that the solution cooling heat exchanger 8 is provided to cool the concentrated solution sent from the concentrated solution pump 61 to the absorber 5. Here, a part of the cooling water sent to the absorber 5 is branched and used as a cooling source for cooling the concentrated solution. Then, the cooling water that has passed through the solution cooling heat exchanger 8 is merged again with the cooling water that has passed through the absorber 5.

In this embodiment thus constructed, the concentrated solution flowing into the absorber 5 is cooled at the inlet of the absorber,
The subcooled state occurs when the concentrated solution flows into the absorber.
As a result, it is possible to prevent self-evaporation when the solution is supplied into the absorber and generation of the solution mist accompanying the self-evaporation, and further it is possible to prevent performance deterioration due to scattering of the solution mist to the evaporator.

In this embodiment, the cooling water used for the cooling source is branched at the absorber inlet and merged at the absorber outlet. However, the cooling water may be branched at the absorber outlet, that is, the condenser inlet and merged at the condenser outlet, or may be branched at the absorber inlet and merged at the condenser outlet.

Still another embodiment of the present invention will be described with reference to FIG. This embodiment is different from the embodiment shown in FIG. 1 in that the cooling water after passing through the second absorber 5b is guided to the condenser 3 without passing through the first absorber 5a, and the condenser 3 is passed through. After that, it is different in that it is guided to the first absorber 5a.

According to this embodiment, since the cooling water is passed through the absorber, the condenser, and the absorber in this order, the outlet temperature of the cooling water can be increased and the temperature difference of the cooling water can be increased. It will be possible. Further, as in the above-described respective embodiments, since the evaporator has a two-stage configuration, the influence of the second evaporator 4b having a high cold water temperature and a high evaporation temperature and pressure does not affect the first evaporator 4a.
Therefore, the pressure in the first evaporator 4a and the evaporation temperature can be kept low, and a temperature difference from the cold water can be secured. This allows
Since the heat transfer area can be effectively used, the number of evaporative heat transfer tubes can be reduced as compared with a single evaporator. This effect is
It is obvious that the temperature difference of cold water is large, and it is obvious in a large temperature difference air conditioning system.

Further, it can be seen from Table 1 that the amount of self-evaporation in the second evaporator when the cold water has a large temperature difference is smaller than that in the case of the standard temperature difference. Therefore, 2
The effect of reducing the generation amount of the refrigerant mist by adopting the stepwise evaporation absorption type becomes remarkable by increasing the temperature difference of the cold water.

That is, if the above embodiments are used in a large temperature difference air conditioning system in which the temperature difference of cold water is large, the effect is increased. In particular, in the embodiment shown in FIG. 7, it is possible to make the temperature difference of the cooling water large, and therefore it is suitable for an air conditioning system in which both the cooling water and the cooling water have a large temperature difference.

FIG. 8 shows still another embodiment of the present invention.
This is an example of a large temperature difference air conditioning system. The large temperature difference air conditioning system includes a multi-stage evaporative absorption absorption chiller / heater 100 that produces cold water or hot water during air conditioning operation, a cooling tower 110 that produces chilled water for the chiller / heater during cooling operation, and a chiller / hot water machine for this chilled water. Cooling water pump 120, an air conditioner 130 for exchanging heat between the cold and warm water generated by the cool and warm water machine and the air, a fan 131 for blowing the heat-exchanged air into the room, and the cool and warm water for heat exchange to the cool and warm water machine 100 again. A cold / hot water pump 140 is provided.

FIG. 8 shows the temperature distribution between the cold water and the cooling water during the cooling operation, and between the elements of the air circulating between the room and the air conditioner 130. By increasing the temperature difference from the conventional 5.5K to 7.4K, the cooling water flow rate is 75%.
Is reduced to. By increasing the temperature difference from the conventional 5K to 8K, the cold water flow rate is reduced to 63%. As a result, it is possible to reduce the transport power of cold water and cooling water and reduce the size of the pipe.

In this embodiment, since the multi-stage evaporative absorption type absorption chiller / heater that does not deteriorate the performance of the evaporator is used as the heat source device of the large temperature difference air conditioning system, even if the cold water has a large temperature difference, Energy efficiency is improved. In the present embodiment, the temperature of the cold water sent from the cold / hot water machine to the air conditioner is 7 ° C., but if the temperature is further lowered, the temperature difference can be further increased and the transport power can be reduced. For example, if the cold water temperature is 5 ° C., the temperature difference from the cold water flowing back from the air conditioner to the cold / hot water machine is 10K, and the flow rate of cold water can be reduced by 50% compared to the conventional case where the temperature difference is 5K. As a result, it is possible to further reduce the transportation power and reduce the installation cost by downsizing the pipe size and the chilled water pump.

[0069]

As described above, according to the present invention, in the multi-stage evaporative absorption type absorption chiller-heater, the self-evaporation of the solution dropped in the absorber can be prevented, so that the absorber can be downsized. Further, according to the present invention, a large temperature difference in cold water makes it possible to provide a low-cost large temperature difference air conditioning system with reduced transport power.

[Brief description of drawings]

FIG. 1 is a system diagram of an embodiment of a multi-stage evaporative absorption type absorption chiller-heater according to the present invention.

FIG. 2 is a detailed view of a portion of the absorption chiller-heater shown in FIG. 1 for discharging non-condensable gas.

FIG. 3 is a perspective view of a refrigerant re-distributor section of the absorption chiller-heater shown in FIG. 1.

FIG. 4 is a diagram for explaining a refrigerant re-distributor of the absorption chiller-heater shown in FIG. 1.

FIG. 5 is a diagram illustrating a dropping condition in the redistribution unit of the absorption chiller-heater shown in FIG. 1.

FIG. 6 is a system diagram of another embodiment of a multi-stage evaporative absorption type absorption chiller-heater according to the present invention.

FIG. 7 is a system diagram of still another embodiment of the absorption chiller-heater of the multi-stage evaporative absorption type according to the present invention.

FIG. 8 is a system diagram of an embodiment of a large temperature difference air conditioning system according to the present invention.

[Explanation of symbols]

1 ... High temperature regenerator, 2 ... Low temperature regenerator, 3 ... Condenser, 4 ... Evaporator, 5 ... Absorber, 6 ... Low temperature heat exchanger, 7 ... High temperature heat exchanger, 31 ... Refrigerant piping, 4a ... 1st Evaporator, 4b ... 2nd evaporator, 41 ... Refrigerant pump, 42 ... Refrigerant discharge piping, 43 ...
Refrigerant distributor, 44a, 44b ... Evaporative heat transfer tube, 45 ... Partition wall, 46 ... Refrigerant re-distributor, 50 ... Eliminator, 5a ...
1st absorber, 5b ... 2nd absorber, 51 ... Dilute solution pump,
53 ... Solution distributor, 54a, 54b ... Absorption heat transfer tube, 56
... Solution re-distributor, 61 ... Concentrated solution pump, 100 ... Multistage evaporative absorption type absorption chiller / heater, 110 ... Cooling tower, 120 ... Cooling water pump, 130 ... Air conditioner, 131 ... Fan, 140 ...
Cold water pump.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Miyake 603, Jinrachi-cho, Tsuchiura-shi, Ibaraki Hitachi Tsuchiura factory (56) References JP-A-9-14792 (JP, A) JP-A-2- 78866 (JP, A) JP 7-332802 (JP, A) JP 1-273972 (JP, A) Actual development Sho 58-74059 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25B 15/00 303 F25B 37/00 F25B 39/02

Claims (13)

(57) [Claims] 1. A multi-stage evaporative absorption-type absorption chiller-heater equipped with an evaporator and an absorber which are vertically formed in multiple stages by partition walls, a condenser, and a regenerator, wherein the multi-stage evaporator and the multi-stage are provided. In the above-mentioned absorber, a pair of evaporator and absorber are formed by the partition walls, and a refrigerant re-distributor for accommodating the refrigerant is formed in the partition walls, and the depth of the refrigerant re-distributor is set to 10 to 100 mm. Characteristic multi-stage evaporative absorption type absorption chiller / heater. 2. The liquid refrigerant is led from the condenser to the highest pressure stage of the evaporator stages formed in multiple stages, and the liquid coolant is led to the upper side through a large number of refrigerant dropping holes provided at the bottom of the refrigerant re-distributor. The multi-stage evaporation type absorption chiller-heater according to claim 1, wherein the refrigerant that has remained as a liquid in the upper evaporator stage is guided from the formed evaporator stage to the lower evaporator stage. . 3. The condenser according to claim 1, wherein the refrigerant is guided from the condenser to an evaporator stage in which cold water refluxing from an air conditioning load system first flows into the evaporator formed in the multiple stages. Multi-stage evaporative absorption type absorption cold / hot water machine. 4. A refrigerant from the condenser to an evaporator stage paired with an absorber stage connected to a solution circulation pump for feeding a dilute solution to the regenerator in the multi-stage absorber. The multistage evaporative absorption-type absorption chiller-heater according to claim 1, wherein 5. A multi-stage evaporative absorption-type absorption chiller-heater comprising an evaporator and an absorber which are vertically formed in multiple stages by partition walls, a condenser, and a regenerator, wherein the multi-stage evaporator and the multi-stage are provided. Each of the absorbers forms a pair of an evaporator and an absorber by the partition wall, and a refrigerant re-distributor for accommodating the refrigerant that has not evaporated in the evaporator above the partition wall, and an absorber above the partition wall. And a solution re-distributor for containing the solution in the vessel,
The depth of the refrigerant re-distributor and the solution re-distributor is 10 to 10
A multi-stage evaporative absorption-type absorption chiller-heater characterized by being set to 0 mm. 6. The multi-stage evaporative absorption-type absorption chiller / heater according to claim 5, wherein each of the multi-staged absorbers is a falling liquid film type absorber stage. 7. The refrigerant re-distributor is a box-shaped recess formed in a partition wall, and the bottom surface of the recess is located at a plurality of heat transfer tube positions in an evaporator stage located below the refrigerant re-distributor. The multistage evaporative absorption-type absorption chiller-heater according to claim 5, wherein a large number of liquid dropping holes are formed correspondingly. 8. The solution redistributor is a box-shaped recess formed in a partition wall, and the bottom surface of the recess is located at a plurality of heat transfer tube positions of an absorber stage located below the solution redistributor. The multistage evaporative absorption-type absorption chiller-heater according to claim 5, wherein a large number of liquid dropping holes are formed correspondingly. 9. An absorber stage, which is paired with an evaporator through which a fluid to be cooled last flows, among the evaporator stages formed in multiple stages,
A solution cooling heat exchanger for exchanging heat between the solution guided to the absorber stage and the cooling water is an absorber stage to which the solution refluxed from the regenerator is first introduced. The multistage evaporative absorption type absorption cold / hot water machine according to 1 or 5. 10. A container containing an evaporator and an absorber is divided into a plurality of spaces each including a part of the evaporator and a part of the absorber to form a plurality of evaporators and absorbers. In a multi-stage evaporative absorption-type absorption chiller-heater configured such that each space operates at a different pressure during operation, cooling water is first passed through a part of the plurality of absorbers, and then condensed once. A multi-stage evaporative absorption-type absorption chiller / heater characterized in that a cooling water flow path is configured so that water is passed through the vessel and the rest of the plurality of absorbers is sequentially passed through. 11. A temperature difference between an outgoing temperature and a returning temperature of cold water that reciprocates between a heat source system and a load system is 5 in a rated operating state.
A large temperature difference air conditioning system larger than K, comprising a multi-stage evaporative absorption-type absorption chiller / heater having an evaporator and an absorber formed in multiple stages in the vertical direction by partition walls, a condenser, and a regenerator. In this absorption chiller-heater, the multi-stage evaporator and the multi-stage absorber each form a pair of an evaporator and an absorber by the partition wall, and a refrigerant re-distributor that stores a refrigerant is formed in the partition wall. Refrigerant redistributor depth is 10-100m
A large temperature difference air conditioning system characterized by being m. 12. A temperature difference between an outgoing temperature and a returning temperature of cold water that reciprocates between a heat source system and a load system is 5 in a rated operation state.
A large temperature difference air conditioning system larger than K, comprising a multi-stage evaporative absorption-type absorption chiller / heater having an evaporator and an absorber formed in multiple stages in the vertical direction by partition walls, a condenser, and a regenerator. The multi-stage evaporator and the multi-stage absorber each form a pair of evaporator and absorber by the partition wall, and a refrigerant re-distributor for accommodating the un-evaporated refrigerant in the evaporator above the partition wall in the partition wall. And a solution re-distributor for accommodating the solution in the absorber on the upper side of the partition wall, and the depth of the refrigerant re-distributor and the solution re-distributor was set to 10 to 100 mm. Differential air conditioning system. 13. A temperature difference between an outgoing temperature and a returning temperature of cold water that reciprocates between a heat source system and a load system is 5 in a rated operating state.
In a large temperature difference air conditioning system that is larger than K, an evaporator and an absorber formed in multiple stages in the vertical direction by partition walls,
An absorption chiller-heater having a condenser and a regenerator, in which the multistage evaporator and the multistage absorber each form a pair of evaporator and absorber by the partition wall, is used as a heat source unit of the heat source system. A large temperature difference air conditioning system that is characterized by