JP2002115868A - Desiccant air conditioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a desiccant air conditioning system which uses desiccant material being high in heat transfer efficiency and having a long life in the case of repeated use as a moisture absorbent, and does not discharge carbon dioxide when utilizing exhaust heat, and is small in occupation area, and is high in energy utilization efficiency, and is simple of operation at the time of working it. SOLUTION: In a desiccant air conditioning system which conditions air by the device where at least a desiccant appliance and a humidistat are arranged in series and each is coupled by fluid passage, desiccant material is arranged in the desiccant appliance, and this system leads the damp air from air-conditioning space into the desiccant appliance, and heats it by the hot discharged air from a heat source, and dehumidifies it by the desiccant material arranged within the desiccant appliance into dry air, and leads this dry air into the humidistat for regulation of humidity, and makes it cold blast by the latent heat in evaporation of water, and supplies this cold blast into the air- conditioning space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a desiccant air conditioning system. More specifically, the present invention relates to a desiccant air-conditioning system that repeatedly uses a desiccant material while regenerating it by dehumidifying and drying it by using heat from a heat source.

[0002]

2. Description of the Related Art Since the summertime in Japan is hot and humid, the use of air conditioners has been widely spread in order to provide a comfortable living environment for consumers, and the demand for electric power has also increased. To meet this growing demand for electricity,
They must rely on hydropower, thermal power, and nuclear power. Hydropower and nuclear power have the disadvantage that they have to be large-capacity power generation facilities, increase investment, and have to be transmitted over long distances. Thermal power generation using oil, coal, natural gas, etc. emits a large amount of carbon dioxide, and under the current situation where the total emission must be reduced, it is not possible to dramatically expand the facilities. However, it is painful for consumers who are accustomed to a comfortable living environment to return to life without using the air conditioner. Therefore, development of a new air conditioning system that does not emit carbon dioxide has been desired.

Recently, a desiccant air-conditioning system, which is a technology for producing cooling heat in a cooling area without using electric power, instead of the air-conditioning equipment using electricity generated by the large-capacity power generation equipment, has been proposed and put into practical use. I have. One of them is LiB
r is a wet type of a solution circulation type, and the other is a dry type of a rotary type of a hygroscopic material (JP-A-5-30101).
No. 4). All of these proposed desiccant air conditioning systems require indirect or clean exhaust heat as a heat source when regenerating (or heating and drying) the moisture absorbing material (desiccant material). It is a large facility, and the hygroscopic material has a drawback that its heat transfer efficiency is low and its life when used repeatedly is short. Further, the latter desiccant air-conditioning system using a moisture absorbent has disadvantages in that frequent valve switching operation is required, the operation is complicated, and the energy use efficiency is low.

[0004]

SUMMARY OF THE INVENTION In such a situation, the present inventors have provided an improved desiccant air-conditioning system which has solved the above-mentioned drawbacks existing in the conventional desiccant air-conditioning system at once. As an object, the present inventors have completed the present invention as a result of intensive studies. That is, the objects of the present invention are as follows. 1. To provide an air conditioning system that does not emit carbon dioxide. 2. To provide a desiccant air conditioning system that occupies a small area. 3. To provide a desiccant air-conditioning system that has a high heat transfer efficiency and a long life when used repeatedly. 4. To provide a desiccant air-conditioning system that is easy to operate and has high energy use efficiency.

[0005]

According to the present invention, there is provided a desiccant air conditioning system in which at least a desiccant device and a humidifier are arranged in series and air-conditioned by a device connected to each other by a fluid flow path. In, desiccant material is placed in the desiccant device,
The moist air from the air-conditioned space is introduced into the desiccant unit, dehumidified by the desiccant material placed in the desiccant unit to form dry air, and the dry air is guided to a humidifier to control the humidity and cool air by the latent heat of evaporation of water. And a desiccant air conditioning system characterized by supplying the cold air to the air conditioning space.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the desiccant air conditioning system according to the present invention, at least a desiccant device and a humidifier (humidifier) are arranged in series,
This is a system for air-conditioning an air-conditioned space (a facility using an air-conditioner) with devices sequentially connected by a fluid flow path. The desiccant device has a desiccant material disposed therein and functions to dry wet air returned after being circulated through an air-conditioned space described later. The humid air returned from the conditioned space has a temperature of about 25-30 ° C and a relative humidity of 6
It is about 0 to 80%. A heat sink (heat exchanger) may be arranged between the desiccant and the humidifier. When the temperature of the dry air passing through the desiccant device is high, the heat remover functions to cool the dry air to an appropriate temperature and guide the humidifier.

[0007] As a desiccant device having the above function,
(1) between the plates of the plate heat exchanger, the desiccant material described below is formed into a pellet and arranged, (2)
A desiccant material described later is formed and arranged in a honeycomb shape between the plates of the plate type heat exchanger. (3) A glass fiber matrix is used between the plates of the plate type heat exchanger, and the desiccant material is combined. And (4) those obtained by appropriately combining the above (1) to (3). When the plate-type heat exchanger of the desiccant device is formed of a honeycomb, it is preferable to alternately arrange the portion (a) for filling the desiccant material and the portion (b) for passing outside air.

A desiccant material is filled in a desiccant device.
By alternately arranging the part (a) and the part (b) through which outside air passes, a heat removal function can be provided. (a) part and
By alternately arranging the (b) part and the (a) part, the heat of adsorption generated when the desiccant material absorbs moisture when the humid air is passed through, the outside air in the (b) part is opposite to the humid air. (Direction of countercurrent) can be cooled to an appropriate temperature.

In the desiccant device having such a structure, humid air having a temperature circulating from the air-conditioned space of about 25 to 30 ° C. and a relative humidity of about 60 to 80% is introduced, and a temperature of about 35 to 35% is introduced.
Dry air having a relative humidity of about 5 to 25% at ~ 55 ° C. Since the desiccant material placed in the desiccant device absorbs moisture from the humid air, a high-temperature exhaust gas (exhaust heat) from a heat source, for example, an exhaust gas at 100 to 250 ° C. is introduced to dehumidify the absorbed moisture. -It can be dried to regenerate the desiccant material.

In the desiccant device, the moisture of the humid air introduced back from the air-conditioned space is converted into dry air by a desiccant material disposed inside, and the moisture of the desiccant material absorbed is removed by introducing a high-temperature exhaust gas. It functions to regenerate wet and dry. Any of the following methods can be used to introduce two types of gases having different properties into the desiccant device. (1) A plate-type desiccant unit is divided into two parts, and wet air is introduced into one section and high-temperature exhaust gas is introduced into the other section, and gas is introduced by rotating the desiccant unit half a turn at a certain operation interval. Method of switching the mouth and introducing two types of gas alternately, (2) The desiccant device is not a divided structure but a fixed type, two or three sets of desiccant devices are arranged in parallel, and the gas introduced into each set is A method of switching sequentially at regular operation intervals.

According to the above method (1), while wet air is introduced into one section to absorb moisture into the desiccant material to make it dry air, in the other section, the absorbed desiccant material is removed by high-temperature exhaust gas. It can be dehumidified, dried and regenerated. The method (2) is the same as the method (1). Since the desiccant material dehumidified, dried, and regenerated by high-temperature exhaust gas is in an overheated state, a step of introducing outside air to lower the temperature to an appropriate temperature without directly introducing wet air may be added. it can.

If the air circulated in the desiccant air-conditioning system is limited to only the humid air returned from the air-conditioned space, the proportion of carbon dioxide contained in the air circulated in the air-conditioned space gradually increases. It is preferable that a part of the humid air returned from the air-conditioned space to be discharged is appropriately released to the outside air, and air corresponding to the released amount is taken in from the outside air.

The desiccant material disposed in the desiccant device has a high moisture absorption / dehumidification / drying property, is a material capable of stably transferring heat, and is required to be capable of being repeatedly used and having a long life. is there. According to the experiments performed by the present inventors, compounds having a maximum moisture absorption (adsorption) amount of 15% by weight or more at room temperature and a relative humidity of 80% were selected, and a large number of small holes were formed on the surface. It has been found that a porous material having the above is preferable. If the maximum moisture absorption is less than 15% by weight, the moisture absorption / dehumidification properties are inferior and are not preferred.

Specific examples of such compounds having surface moisture absorption properties include activated carbons having various surface moisture absorption properties, silica gels having various surface moisture absorption properties, carbon fibers having various surface moisture absorption properties, and Na. Zeolite,
Zeolites such as Ca zeolite and Mg zeolite; oxides such as aluminum oxide (Al ₂ O ₃ ) and magnesium oxide (MgO); and clay minerals such as mordenite and allophane. Desiccant wood is
It is not limited to the illustrated one as long as it has the above-mentioned surface moisture absorption characteristics. The desiccant material is
One kind or two or more kinds can be combined.

In order to make these desiccant materials highly functional,
It is possible to increase the surface area by making the film thinner or more porous, and to promote the adsorption and dehumidification of moisture by exchanging cations or anions and increasing the surface area. The desiccant material is mainly in the form of a powder, a pellet, or a honeycomb, and is arranged in the space of the plate-type desiccant device. It is preferable that the powdery material is combined with a glass fiber matrix to form a honeycomb structure and disposed in a space portion of a plate type desiccant device, and the pelletized desiccant material is filled in a space portion partitioned by a plate. It is preferable to arrange them.

The heat source of the high-temperature exhaust gas for dehumidifying and drying the desiccant material having absorbed moisture is mainly a micro gas turbine, a gas turbine, a diesel engine, a gas engine, a fuel cell, a heat pump, a waste power generation facility. In addition to high-temperature exhaust gas (exhaust heat) from on-site decentralized power generation facilities, such as solar heat, steelworks, petrochemical plants, cement factories, and other gas, heavy oil, and waste from incineration facilities High temperature exhaust gas (exhaust heat). Among the heat sources, micro gas turbines, fuel cells, heat pumps and the like are preferable, and micro gas turbines and fuel cells are particularly preferable. The temperature of the high-temperature exhaust gas varies depending on the type of the heat source.
C. or higher, preferably 150 ° C. or higher. One of these heat sources may be installed depending on the size of the air-conditioned space (utilization facility), or a plurality of same or different types of equipment may be installed in combination.

A micro gas turbine as a heat source has three
With a power of about 0 kW, it is a typical equipment of on-site decentralized power generation equipment. It is a device that burns various fuels such as city gas, propane gas, kerosene, light oil, etc. and rotates the turbine to generate power. Approximately 25% of the heat is used as power generation output, and about 50% of the high-temperature exhaust heat is used for hot water supply and heating, but about 25% is used for radiation, exhaust gas loss, mechanical loss, and conversion loss. Had been lost. In the present invention,
Energy that is not used as a power generation output but is equivalent to about 50% or more of fuel conventionally used for hot water supply and heating is effectively used as a heat source for producing cold air (cool air).

A fuel cell as a heat source is a power generation system that converts chemical energy having hydrogen or the like to the electric energy by applying the principle of electrochemical power generation. Fuel cells are classified according to the type of electrolyte, such as (a) phosphoric acid type, (b) molten carbonate type, (c) solid electrolyte type, (d) solid polymer type, etc. The heat source may be any type of fuel cell. The principle of the fuel cell is that, taking the above-mentioned (a) phosphoric acid type as an example, the reverse reaction of water electrolysis is used. And oxygen is supplied to generate electric power. The operating temperature in (a) depends on the type of raw fuel (natural gas, LPG, methanol, naphtha, light oil, etc.), but is 170 to 210 ° C., and high-temperature exhaust heat is used as a heat source.

A heat pump as a heat source is a device that absorbs the heat of a low-temperature heat source by external mechanical, thermal or electrical energy and increases the temperature to give it to a high-temperature portion. The increased heat is used as a heat source. Available. In addition to the above, high-temperature exhaust gas emitted from various factories such as steelworks, petrochemical plants, and cement factories, and high-temperature exhaust gas emitted from waste incineration equipment and the like can be given as examples of the heat source.

As described above, high-temperature exhaust gas (exhaust heat)
Is passed through the space of the plate-type structure of the desiccant device, heats the desiccant material that has absorbed moisture, dehumidifies (desorbs), dries, and regenerates. After passing through the desiccant device, it is exhausted to the atmosphere, but if the temperature of the exhaust gas is higher, it can be passed through another heat exchanger and used as hot water or hot air for other uses. .

The desiccant unit of the desiccant air-conditioning system according to the present invention includes a part (a) filled with a desiccant material,
By alternately arranging the portion (b) through which outside air passes, a heat removal function can be provided. By arranging the (a) part and the (b) part alternately, the heat of adsorption generated when the desiccant material absorbs moisture when the humid air is passed through the (a) part,
By passing the outside air or water through the portion (b) in the direction opposite to the humid air (countercurrent), it is possible to cool to an appropriate temperature.

In the desiccant air conditioning system according to the present invention, a humidifier (humidifier) is arranged after the desiccant device.
They are connected by a fluid channel. In this humidifier, water is evaporated by bringing dry air having a temperature from a desiccant device of about 35 to 55 ° C. and a relative humidity of about 5 to 25% into direct contact with water, and the latent heat of evaporation of the water causes the temperature to evaporate. Is about 15 to 28 ° C. and the relative humidity is about 40 to 100%, and the cool air is circulated and supplied to the air-conditioned space through a fluid flow path.

In the present invention, the term "air-conditioned space" refers to a facility in which an air conditioner is installed to use cold air for cooling or air conditioning in a clean room. Specific examples of air-conditioned space include hospitals, public halls, libraries, various halls such as cultural halls where many people gather, public facilities such as schools, kindergartens, gymnasiums, nursing homes, apartment houses, office buildings, hotels, restaurants, department stores , Supermarkets, convenience stores, pachinko game arcades, various factories, various commercial facilities, and the like. The air conditioning space in which the desiccant air conditioning system according to the present invention is arranged is not limited to the facilities exemplified above.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following description unless it exceeds the gist.

FIG. 1 is a schematic view of an example of a desiccant air-conditioning system according to the present invention. FIG. 2 is a schematic diagram showing a desiccant material placed in a desiccant unit to humid air introduced after being circulated in an air-conditioned space. FIG. 3 is a schematic diagram showing the flow of gas when it is converted to air.
It is a schematic diagram showing the flow of gas when drying and regenerating,
FIG. 4 is a schematic diagram showing the flow of gas when cooling the superheated desiccant material disposed in the desiccant device.

FIG. 5 is a perspective view of an example of the desiccant device, FIG. 6 is a schematic diagram showing the flow of circulating air when the desiccant device dehumidifies the humid air, and FIG. 7 shows the desiccant material in the desiccant device. FIG. 9 is a schematic diagram showing a flow of a high-temperature exhaust gas when drying, dehumidifying, and regenerating. FIG. 8 is a schematic diagram showing an example of a change in temperature and humidity when air conditioning is performed by a desiccant air conditioning system. FIG. 1 is a schematic view of an example of a conventional desiccant air conditioner.

In the figure, desiccant air conditioning system 1
Is constituted by a desiccant device 2, a dehumidifier 3, and a humidity controller 4. The desiccant device 2 is, for example, 700 mm ×
700mm x 700mm cube, 1 depending on the plate
It is divided into five stages. In the desiccant device 2, zeolite having a maximum moisture absorption of 15% by weight under the conditions of room temperature and a relative humidity of 80% is disposed as a desiccant material in a space portion of the plate-type heat exchanger structure (see FIG. 5). ). When a plate-type heat exchanger structure is used, a block may be formed by several plates, and a gap may be provided between mutually adjacent blocks (see FIGS. 6 and 7). Wet air
The moisture can be adsorbed on the desiccant material by passing through the space of the desiccant device 2 where the desiccant material is arranged (see FIG. 6).

The circulating air is supplied to the fluid passage 6 by the fan 5.
Is forcibly moved in the direction of the arrow. The humid air to be circulated back from the air-conditioned space is partially mixed with outside air for ventilation, and is introduced into the desiccant device 2 from the circulating air inlet. Humid air has a temperature of about 30 ° C. and a relative humidity of about 80%. The moist air is dehumidified in the desiccant unit 2 and the relative humidity is about 10%. If the temperature of the circulating air is too high due to the heat of adsorption generated when the desiccant material is humidified, the heat is removed by the heat sink 3. Preferred are as described above.

The dry air dehumidified by the desiccant material arranged in the desiccant device 2 is then passed through a humidifier 4 where the dry air is brought into direct contact with water, such as by spraying the dry air with a mist. Thus, the water is evaporated, and the water is further cooled by the latent heat of evaporation. The air is cooled to a temperature of about 20 ° C. and a relative humidity of about 100% and supplied to the air-conditioned space.

The desiccant material placed in the desiccant unit 2 absorbs the moisture of the humid air from the air-conditioned space, and its moisture absorbing ability gradually decreases. Therefore, for example, a micro gas turbine (for example, manufactured by Takuma, model:
A high-temperature exhaust gas of 250 ° C. from the TCP 30, power generation output: 28 kW) is shown in FIG. 3 as a schematic diagram of the gas flow, and FIG. 7 shows the flow of the high-temperature exhaust gas. And then dehumidify, dry and regenerate depending on the temperature of the exhaust gas. When the temperature of the desiccant material in the desiccant device 2 is overheated, outside air is introduced into the desiccant device 2 to cool the desiccant material, as schematically shown in FIG.

FIG. 8 is a diagram showing changes in the temperature and humidity when circulating air is passed through the desiccant dehumidifier. For example, when circulating air (see point a) having a temperature of 30 ° C. and a relative humidity of about 75% is passed through the desiccant device, the circulating air is dehumidified in the desiccant device, and the heat generated by the moisture absorption heat of the desiccant material. Heat is removed by a heat sink connected after the desiccant unit, and the temperature of the heat sink is 3 at the outlet of the heat sink.
The dry air is 0 ° C. and the relative humidity is about 5% (see point b). When the water is evaporated and humidified by a method such as spraying water in a mist state on the dry air, the temperature becomes about 21 ° C. (c
Point), and the relative humidity can be about 80%.

FIG. 9 is a schematic diagram showing an example of a conventional desiccant air conditioner. 9, reference numeral 91 denotes a conventional desiccant air conditioner; 92, a dehumidifying rotor; 93, a heating unit;
4 is a sensible heat exchanger and 95 is a humidifier. As shown in FIG. 9, the conventional desiccant air conditioner requires frequent valve switching operations to operate the desiccant air conditioner, which is undeniably complicated and has high energy use efficiency. It is hard to say that.

[0033]

As described in detail above, the present invention has the following particularly advantageous effects, and its industrial value is extremely large. 1. Since the desiccant air-conditioning system according to the present invention mainly uses high-temperature exhaust gas (exhaust heat) as a heat source, it does not newly emit carbon dioxide. 2. The desiccant air-conditioning system according to the present invention utilizes the high-temperature exhaust gas discharged from the distributed power generation equipment and the like, and can operate the distributed power generation equipment to reduce the amount of power purchase. Peak power demand can be reduced and overall energy efficiency can be improved. 3. Since the desiccant air-conditioning system according to the present invention uses high-temperature exhaust gas discharged from a distributed power generation facility or the like, compared to a conventional desiccant air-conditioning system, the occupied area is small, the equipment is not large, and the installation cost is low. Because it ’s cheap
It is easy to adopt for air conditioning in a small air conditioning space. 4. The desiccant air-conditioning system according to the present invention has a high heat transfer efficiency of the hygroscopic material, has a long life when used repeatedly, and is advantageous for adoption. 5. The desiccant air-conditioning system according to the present invention is easier to operate and has higher energy utilization efficiency than the conventional desiccant air-conditioning system.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an example of a desiccant air conditioning system according to the present invention.

FIG. 2 is a schematic diagram showing a gas flow when the moisture of the humid air introduced back from the air-conditioned space is converted into dry air by a desiccant material disposed in a desiccant device.

FIG. 3 is a schematic diagram showing a gas flow when desiccant material is dehumidified, dried, and regenerated.

FIG. 4 is a schematic diagram showing a gas flow when cooling a superheated desiccant material arranged in a desiccant device.

FIG. 5 is a perspective view of an example of a desiccant device.

FIG. 6 is a schematic diagram showing a flow of circulating air when dehumidifying humid air by a desiccant device.

FIG. 7 is a schematic diagram showing a flow of a high-temperature exhaust gas when drying, dehumidifying, and regenerating a desiccant material in a desiccant device.

FIG. 8 is a schematic diagram showing an example of a state change of temperature and humidity when air conditioning is performed by a desiccant air conditioning system.

FIG. 9 is a schematic view of an example of a conventional desiccant air conditioner.

[Explanation of symbols]

 1: Desiccant air conditioning system of the present invention 2, 52: Desiccant unit 3: Heat remover 4: Humidifier 5: Fan 6, 96: Fluid passage 91: Conventional desiccant air conditioner 92: Dehumidifying rotor 93: Heating means 94: Sensible heat exchanger 95: Humidifier

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Nobuo Yamada 5-34-6 Shiba, Minato-ku, Tokyo Mitsubishi Chemical Engineering Co., Ltd. F-term (reference) 3L053 BC03 BC06 BC08 4D052 AA09 CE00 DA02 DB01 FA05 GA04 HA03

Claims (7)

[Claims] 1. A desiccant air-conditioning system in which at least a desiccant device and a humidifier are arranged in series and air-conditioned by a device each connected by a fluid flow path, a desiccant material is arranged in the desiccant device, and The moist air is introduced into the desiccant apparatus, and is dehumidified by the desiccant material arranged in the desiccant apparatus to become dry air.The dry air is guided to a humidifier to control the humidity, thereby producing cold air by the latent heat of evaporation of water. A desiccant air-conditioning system characterized by supplying the air to the air-conditioned space. 2. The desiccant air conditioning system according to claim 1, wherein a heat remover is arranged between the desiccant device and the humidifier. 3. The desiccant air conditioning system according to claim 1, wherein the desiccant device has a plate-type heat exchanger structure and has a heat removal function. 4. The desiccant material has a room temperature and a relative humidity of 80%.
The desiccant air-conditioning system according to any one of claims 1 to 3, wherein the maximum moisture absorption amount under the condition of (1) is selected from compounds having 15% by weight or more. 5. The desiccant material according to claim 1, wherein the desiccant material is heated by high-temperature exhaust gas from a heat source, dehumidified, dried, regenerated, and used repeatedly. Desiccant air conditioning system. 6. The heat source is a high-temperature exhaust gas from a distributed power generation facility such as a micro gas turbine, a gas turbine, a diesel engine, a gas engine, a fuel cell, a heat pump, an incinerator power generation facility, or a high-temperature emission from various factories. 6. The gas according to claim 1, wherein the gas is solar heat.
The desiccant air conditioning system according to any one of the above. 7. The air-conditioned space is a hospital, a public hall, a library, a culture hall, a school, a kindergarten, a gymnasium, a retirement home, an apartment house, an office building, a hotel, a restaurant, a department store, a supermarket, a convenience store, a pachinko amusement park, and various factories. The desiccant air conditioning system according to any one of claims 1 to 6, which is a commercial facility or the like.