JP5019261B2 - Desiccant air conditioner - Google Patents

Description

  The present invention relates to a desiccant air conditioner that efficiently performs air conditioning by adsorbing process air with a desiccant.

  As for the desiccant air conditioner, many proposals have been made in Patent Document 1, for example. As a desiccant air conditioner that adjusts humidity and temperature using outside air as processing air to maintain the indoor environment and introduces it into the room, as shown in FIG. A desiccant rotor 10 disposed in a straddling manner and a heat pump 36 that provides a high temperature heat source 42 and a low temperature heat source 46 to the desiccant rotor 10 are well known. The desiccant rotor 10 is a breathable member in which a desiccant material having high moisture absorption and regeneration efficiency is held in a disc-shaped honeycomb structure, and is rotated at a low speed by the motor 14.

  When performing cooling in the summer using this air conditioner, high-temperature and high-humidity outside air (process air) is adsorbed with moisture when passing through the adsorption zone 28 that is a portion in the process air flow path 24 of the desiccant rotor 10, and the heat pump 36 After being cooled by the evaporator 46 which is a low-temperature heat source, it is supplied into the room. On the other hand, the return air from the room is heated by the condenser 42 which is a high-temperature heat source of the heat pump 36 in the regeneration air passage 26 and passes through the regeneration zone 30 which is a part in the regeneration air passage 26 of the desiccant rotor 10. The moisture is desorbed to regenerate the desiccant 10 and exhausted to the outside. Each part of the desiccant rotor 10 alternately repeats moisture adsorption from the processing air and regeneration by the regeneration air while entering and exiting the processing air passage 24 and the regeneration air passage 26 in a constant cycle.

  In such an air conditioner, a heat pump 36 such as a vapor compression refrigerator is used as a heat source, but a high heat source temperature having a high COP (coefficient of performance) is practically about 65 ° C. In such a device, for example, the case where the outside air of 35 ° C. and 22 g / kg DA (dry air) is treated and introduced assuming the highest temperature and humidity outside air conditions in the midsummer of Tokyo is shown in the wet air diagram of FIG. . In this case, assuming that the indoor air has a dry bulb temperature of 27 ° C. and an absolute humidity of 10.5 g / kgDA (5), the regenerated air has only a dry bulb temperature of 60 ° C. and a relative humidity of about 9% (6), and is treated air. Even if the outside air is adsorbed with an isoenthalpy change (1 → 2), it cannot be reduced to the same absolute humidity as indoor air, 10.5 g / kgDA. Therefore, there is a problem that the indoor humidity becomes high, and in order to solve this, a heat pump with a low COP and a high-temperature heat source of 70 ° C. or more are necessary.

  Further, in such an apparatus, in the moisture adsorption process while the processing air flows in the desiccant rotor 10, the difference in moisture content between the desiccant that serves as a driving force for adsorption and the processing air gradually decreases, and the desiccant rotor 10 The amount of moisture adsorbed at the outlet side portion is greatly reduced. For this reason, only the air inflow side portion of the desiccant rotor 10 contributes to the adsorption of the processing air, and the desiccant rotor as a whole cannot sufficiently absorb and desorb moisture, and the required desiccant amount per dehumidification amount increases, resulting in cost reduction. It was hanging.

JP-A-9-196482

The present invention has been made in view of the above circumstances, and can take a large dehumidification / humidity difference even with a low-temperature heat source. It aims at providing the desiccant air conditioner which can dehumidify to humidity (for example, 10.5g / kgDA) or less.
Another object of the present invention is to provide a desiccant air-conditioning apparatus which can take a large difference in operating humidity of the desiccant and thereby can perform sufficient dehumidification with a small desiccant and is inexpensive.

In order to achieve the above object, a desiccant air conditioner according to claim 1 is provided with a processing air passage through which processing air flows, a regeneration air passage through which regeneration air flows, and these processing air passage and regeneration air passage. A desiccant rotor that rotates so as to intersect the processing air, and the processing air passage adsorbs moisture of the processing air when the processing air sequentially passes through the first and second adsorption zones of the desiccant rotor. The regeneration air flow path is configured so that moisture of the desiccant rotor is desorbed when the regeneration air passes through the regeneration zone of the desiccant rotor, and further, the regeneration air before entering the regeneration zone. And a low heat source heat exchanger that cools the processing air between the first adsorption zone and the second adsorption zone. In the adsorption zone is configured to flow so that their process air forms a counterflow, between said first and second adsorption zones, so as to restore the suction driving force of the desiccant,
Further, in the second adsorption zone, the treatment air flows from the outlet side in the first adsorption zone where the desiccant water content is relatively small, thereby correcting the uneven distribution of the water content in the thickness direction of the desiccant rotor, and the entire desiccant rotor. It is characterized by increasing the water content of .

  In the first aspect of the invention, after the moisture is adsorbed when the processing air passes through the first adsorption zone of the desiccant rotor, the processing air is further cooled when passing through the low heat source heat exchanger. Then, the moisture adsorbs in a state where the adsorbing driving force of the desiccant is improved after flowing into the second adsorption zone and finishing the adsorption treatment in the first adsorption zone. Thereby, the adsorption reaction rate can be improved and the overall dehumidification performance can be improved as compared with the conventional case where the adsorption process is continued in a state where the adsorption driving force is reduced.

In addition, in the first aspect of the invention, the first and second adsorption zones flow so that the processing air flows in a counter flow, so that the second adsorption zone is a process in the first adsorption zone. Process air flows in from the outlet side having a relatively small water content, and efficient moisture adsorption is performed in which the water content is evenly distributed in the thickness direction of the desiccant.

The desiccant air conditioner according to claim 2 is the invention according to claim 1, wherein the regeneration zone is composed of first and second regeneration zones that are adjacent to each other and in which the regeneration air flows in a counterflow, And a second high heat source heat exchanger for heating the regeneration air between the first regeneration zone and the second regeneration zone.

In the invention described in claim 2 , after the moisture is desorbed when the regeneration air passes through the first regeneration zone of the desiccant rotor, the regeneration air further passes through the second high heat source heat exchanger. The moisture is desorbed in a state in which the regeneration driving force of the desiccant is improved after flowing into the second regeneration zone after being heated to and after finishing the desorption process in the first regeneration zone. As a result, the desorption reaction rate can be improved and the overall dehumidification performance can be improved compared to the conventional case where the desorption process is continued in a state where the regeneration driving force is reduced.

A desiccant air conditioner according to a third aspect of the present invention includes the heat pump according to the first or second aspect , wherein the low heat source heat exchanger is a low heat source and the high heat source heat exchanger is a high heat source. It is characterized by that.

In invention of Claim 3 , a compact and practical desiccant air conditioner can be provided by making the low heat source heat exchanger of a heat pump into a low heat source, and making a high heat source heat exchanger into a high heat source.

According to the desiccant air conditioner according to any one of claims 1 to 3 , a large difference in dehumidifying humidity can be obtained even with a low-temperature regenerative heat source. An indoor environment can be provided. In addition, it is possible to provide a desiccant air-conditioning apparatus which can take a large difference in operating humidity of the desiccant and thereby can perform sufficient dehumidification with a small amount of desiccant and which is inexpensive.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a desiccant air conditioner according to a first embodiment of the present invention, in which a disc-shaped desiccant rotor 10 is coaxial with a casing 12 (only a part of which is shown) forming a cylindrical inner space. The motor is a drive device and is rotated gently. As the desiccant rotor 10, a well-known one in which a predetermined porous desiccant (adsorbent) is formed into a disk-shaped member having a honeycomb-like reinforcing structure can be used.

  In the casing 12, partition plates 16 a, 16 b, 18, 20, and 22 that partition the internal space before and after the desiccant rotor 10 by planes including the axis line are provided. In the figure, in the space on the left side of the desiccant rotor 10, there are a pair of partition plates 16a and 16b extending in the horizontal direction and partition plates 18 and 20 extending in the vertical direction, so that each of the four has a fan-shaped cross section with a central angle of 90 degrees. A partial space is formed. On the other hand, in the space on the right side of the desiccant rotor 10, there is one partition plate 22 extending in the horizontal direction, and two partial spaces are formed on the top and bottom. The partition plates 16a, 16b, and 22 extending in the horizontal direction divide the internal space into an upper processing air flow path 24 and a lower regeneration air flow path 26. In addition, due to the sealing structure of the vertical partition plates 18 and 20 and the right casing 12, the upper and lower processing air flow paths 24 and the regeneration air flow path 26 pass through the desiccant rotor 10 twice and make U-turns. It is formed as.

  Since the portion of the desiccant rotor 10 in the processing air flow path 24 comes into contact with the high-temperature and high-humidity processing air and adsorbs moisture in the processing air, this portion is called an adsorption zone, and the desiccant rotor in the regeneration air flow path 26 Since the portion 10 comes into contact with the low-temperature and low-humidity regeneration air and desorbs moisture in the regeneration air, the portion is referred to as a regeneration zone. In this embodiment, the first and second adsorption zones 28a and 28b and the first and second regeneration zones 30a and 30b are formed by the vertical partition plates 18 and 22, respectively. The inlets of the processing air and the regeneration air are provided corresponding to the first adsorption zone 28a and the first regeneration zone 30a, respectively, and the fans 32 and 34 are provided respectively.

  In this embodiment, the first adsorption zone 28a and the second adsorption zone 28b are adjacent to each other in the reverse order in the rotational direction of the desiccant rotor 10, and the first regeneration zone 30a and the second regeneration zone 30b are the same as those of the desiccant rotor 10. Adjacent to the rotation direction in the same order. Therefore, the desiccant on the desiccant rotor 10 rotates in the order of the second adsorption zone 28b → the first adsorption zone 28a → the first regeneration zone 30a → the second regeneration zone 30b. Such an arrangement is better than the case where the first and second adsorption zones and the regeneration zone as shown in FIG. 2 are adjacent in the same order along the rotational direction of the desiccant rotor 10 in the experiments so far. A grade was obtained.

  A low heat source and a high heat source of a vapor compression refrigeration machine (heat pump) 36 are respectively disposed in the processing air flow path 24 and the regeneration air flow path 26 formed as described above, and the air and heat in these flow paths are arranged. It is supposed to exchange. The heat pump 36 includes a compressor 40, first and second condensers (high heat source heat exchangers) 42a and 42b, an expansion valve 44, and an evaporator (low heat source heat) in a refrigerant flow path 38 through which a predetermined refrigerant circulates. 46) are sequentially provided. The evaporator 46 is disposed in a space between the first adsorption zone 28 a and the second adsorption zone in the processing air flow path 24, and the first condenser 42 a is disposed in the regeneration air flow path 26. On the upstream side of the first regeneration zone 30a, the second condenser 42b is disposed in a space between the first regeneration zone 30a and the second regeneration zone 30b.

  Hereinafter, as in the case of the conventional example, the desiccant air conditioner shown in FIG. 1 is used in an air conditioning operation in which an outside air of 35 ° C. and 22 g / kgDA is introduced by assuming the highest temperature and humidity outside air condition in the midsummer season of Tokyo. The result of simulating the operation based on empirical data will be described with reference to the wet air diagram of FIG. The indoor air is set to a dry bulb temperature of 27 ° C. and an absolute humidity of 10.5 g / kgDA (5). Moreover, in the following description, the code | symbol showing each place of the apparatus shown by FIG. 1 and FIG. 3 is shown in a sentence.

  The indoor air taken into the regeneration air flow path 26 by the blower 34 as the regeneration air from the indoor space is heated in the first condenser (6) and passes through the first regeneration zone 30a of the desiccant rotor 10. Then, the moisture of the desiccant rotor 10 is desorbed and the temperature is lowered in the process of isoenthalpy (6 → 7). The room air further rises in temperature in the second condenser 42b (8), desorbs moisture from the desiccant rotor 10 when passing through the second regeneration zone 30b of the desiccant rotor 10, and decreases in temperature during an isoenthalpy process. After (8 → 9), it is exhausted to the outside.

  In the currently available vapor compression refrigerator, when two heat sources are set in this way, this vapor compression refrigerator uses a heat pump having the same capacity as the conventional one, and the enthalpy difference Δh is reduced. In this case, since the high heat source is divided, the high heat source temperature, in particular, the second high heat source temperature is lowered by ΔT and is operated at about 55 ° C. The operating condition of such a heat pump is within a range where it can be operated at a high COP by a vapor compression refrigerator.

  On the other hand, when the hot and humid outside air (1) taken into the processing air flow path 24 by the blower 32 as processing air from the outdoor space passes through the first adsorption zone 28a of the desiccant rotor 10, the first regeneration zone. An amount of water substantially corresponding to the amount desorbed in 30a is adsorbed, and the temperature rises in the isoenthalpy process (1 → 2). The treated air is further cooled in the evaporator 46 to condense moisture along the saturation line (3), and then passes through the second adsorption zone 28b of the desiccant rotor 10 to further the second regeneration zone 30b. Moisture in an amount substantially corresponding to the amount desorbed in is adsorbed and the temperature rises in the isoenthalpy process (3 → 4).

  According to the simulation result, the outdoor air of 22 g / kgDA at the time of midsummer is set to the normal indoor setting of 10.5 g / kgDA using a relatively low temperature heat source by the adsorption twice in the first and second adsorption zones a and b. It was possible to dehumidify to the following. The reason for this is that by performing the process air adsorption and desiccant desorption processes in two zones, respectively, the efficiency in each of the adsorption and desorption processes is increased as compared with the conventional case shown in FIG. This is explained in detail below.

  The process of moisture adsorption and desorption by the desiccant rotor 10 is a non-equilibrium process in which the desiccant does not reach a completely equilibrium state because it is performed at a limited time in which each desiccant exists in each flow path. Therefore, the efficiency of adsorption or desorption depends on the rate of these reactions, which is the difference between the maximum water content α that can be adsorbed by the desiccant and the actual water content β (α−β) (hereinafter referred to as adsorption driving force). )). The maximum moisture content α that can be adsorbed is proportional to the relative humidity of the desiccant as shown in FIG.

  First, the adsorption process will be described. Since the adsorption phenomenon proceeds from the air inlet side in the desiccant rotor 10, the relative humidity decreases from the inlet to the outlet in the thickness direction of the desiccant, and thus the maximum moisture content α also decreases. To do. In addition, the actual moisture content β naturally increases sequentially from the inlet side as the process proceeds, and also increases as a whole, so that the adsorption driving force decreases as the process proceeds.

  For example, in the conventional example shown in FIG. 8, since the relative humidity on the outlet side at the end of the adsorption process is 9%, the maximum moisture content α is reduced to 3.6%, and the actual moisture content β Regardless of the value, it is judged that the efficiency of the adsorption treatment in the final stage was considerably low.

  In contrast, in the apparatus of FIG. 1, the first stage adsorption process is completed in about half the time of the conventional case, and the relative humidity on the outlet side at this time is about 30%, so the maximum moisture content α is 12%. % Is still high and the adsorption driving force is also high. Then, since the relative humidity increases (up to 100% in this example) by cooling the processing air by the evaporator 46, the maximum moisture content α of the second adsorption zone 28b as shown by a point C in FIG. Is 40%, and the adsorption process is continued in a state where the adsorption driving force of the desiccant is recovered. In this way, even if the total processing time or the amount of desiccant is the same, the processing air is cooled between the two processings instead of continuing the processing in a state where the suction driving force is reduced as in the conventional case. As a result, the adsorption driving force is recovered and the reaction speed is increased, so that it is considered that a higher adsorption action can be obtained in a predetermined processing time.

  Further, as a second reason for improving the adsorption efficiency, in this embodiment, the processing air flow path 24 is reversed downstream of the first adsorption zone 28a, so that the second adsorption zone 28b and the first adsorption zone 28a It is mentioned that it is made to flow in from the opposite side. As described above, the actual moisture content β is low on the outlet side of the adsorption zone, so that the adsorption driving force is increased by increasing the maximum moisture content α by cooling, thereby correcting the uneven distribution of the adsorption amount. The entire desiccant can be used to increase the amount of adsorption.

  Next, the desorption process will be described. The concept of the desorption process is basically the same as that of the adsorption process. That is, if the desorption driving force is defined as the difference between the maximum moisture content α ′ and the actual moisture content β ′ at that time as in the case of the adsorption driving force shown in FIG. By adopting the regeneration step, a higher desorption amount can be achieved than in the conventional case where desorption is performed once using a high-temperature heat source. This can be understood by comparing the vertical axis position (absolute humidity) of point (7) in FIG. 9 in the conventional case and point (9) in FIG. 3 of the present invention, that the latter is at a higher position.

  In the embodiment of FIG. 1, the ratio between the adsorption zone and the regeneration zone is set to be equal, which means that the adsorption and desorption processes are the same. However, the optimal adsorption / desorption treatment time ratio varies depending on the characteristics of the desiccant material used, the temperature conditions of the heat source, etc., so it is desirable to set them appropriately according to these conditions. Similarly, the ratio of the first and second zones in each zone can be set to an appropriate ratio. These adjustments can be easily performed by changing the center angle of each zone by changing the positions of the partition plates 16a, 16b, 18, 20, and 22. In this embodiment, the temperature of the treated air after the adsorption treatment is higher than that of the room air. This is manifested by providing a second low heat source heat exchanger at the outlet of the second adsorption zone 28b, for example. This can be dealt with by removing heat.

  For example, when the desiccant material has sufficient adsorption or desorption performance, the zone may be divided into only one of the steps. FIG. 5 shows a case where only the adsorption zone is divided when a desiccant having high desorption performance is used. Further, FIG. 6 is such that the positions of the inlet / outlet of the regeneration air passage 26 and the processing air passage 24 are on the opposite side with respect to the embodiment of FIG. This simply considers the convenience of external piping to these air flow paths, and either the type shown in FIG. 1 or the type shown in FIG. 6 may be selected according to the situation.

  Moreover, in said embodiment, although the vapor | steam compression refrigerator 36 which is a heat pump which can supply a low heat source and a high heat source as a heat source was used, of course, another type of suitable heat pumps can be used. In addition, an energy saving effect can be obtained by appropriately adopting individual heat sources available in a situation where the air conditioner is installed. FIG. 7 is an embodiment showing such a configuration, in which, for example, low-temperature waste heat 48 from a factory is used as a high heat source, and ground heat 52 and groundwater are used as a low heat source.

It is a figure which shows the structure of the desiccant air conditioner of embodiment of this invention. It is a figure which shows the structure of the modification of the desiccant air conditioner of FIG. It is a humid air line figure explaining operation | movement of the desiccant air conditioner of FIG. It is a figure explaining the adsorption drive force in the desiccant air conditioner of FIG. It is a figure which shows the structure of the desiccant air conditioner of 2nd Embodiment of this invention. It is a figure which shows the structure of the desiccant air conditioner of 3rd Embodiment of this invention. It is a figure which shows the structure of the desiccant air conditioner of 4th Embodiment of this invention. It is a figure which shows the structure of the conventional desiccant air conditioner. It is a humid air line figure explaining operation | movement of the desiccant air conditioner of FIG.

Explanation of symbols

10 Desiccant rotor 12 Casing 14 Motor 16a, 16b, 22 Partition plate (horizontal)
18, 20 Partition plate (vertical)
24 treatment air passage 26 regeneration air passage 28 adsorption zone 28a first adsorption zone 28b second adsorption zone 30 regeneration zone 30a first regeneration zone 30b second regeneration zone 32, 34 blower 36 heat pump (vapor compression refrigeration Machine)
38 Refrigerant flow path 40 Compressor 42 Condenser (high heat source heat exchanger)
42a First condenser (first high heat source heat exchanger)
42b 2nd condenser (2nd high heat source heat exchanger)
44 Expansion valve 46 Evaporator (low heat source heat exchanger)
48 Low temperature waste heat 50a, 50b High heat source heat exchanger 52 Earth heat 54 Low heat source heat exchanger

Claims (3)

A processing air flow path through which processing air flows;
A regeneration air passage through which regeneration air flows;
A desiccant rotor that rotates across the processing air flow path and the regeneration air flow path,
The processing air flow path is configured such that moisture of the desiccant processing air is adsorbed when the processing air sequentially passes through the first and second adsorption zones of the desiccant rotor,
The regeneration air flow path is configured such that the regeneration air desorbs moisture of the desiccant rotor when the regeneration air passes through the regeneration zone of the desiccant rotor,
Furthermore, a high heat source heat exchanger for heating the regeneration air before entering the regeneration zone;
A low heat source heat exchanger for cooling the processing air between the first adsorption zone and the second adsorption zone, wherein the processing air forms a counter flow in the first and second adsorption zones; be one that is configured to flow way,
The desiccant adsorption driving force is restored between the first and second adsorption zones,
Further, in the second adsorption zone, the treatment air flows from the outlet side in the first adsorption zone where the desiccant water content is relatively small, thereby correcting the uneven distribution of the water content in the thickness direction of the desiccant rotor, and the entire desiccant rotor. A desiccant air conditioner characterized in that the water content of the desiccant is increased .
The regeneration zone is composed of first and second regeneration zones that are adjacent to each other and in which the regeneration air flows in a counterflow, and the regeneration air is placed between the first regeneration zone and the second regeneration zone. The desiccant air conditioner according to claim 1, further comprising a second high heat source heat exchanger for heating. The desiccant air conditioner according to claim 1 or 2 , further comprising a heat pump having the low heat source heat exchanger as a low heat source and the high heat source heat exchanger as a high heat source.

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