JP2002115867A - Exhaust heat utilization type cogeneration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust heat utilization type cogeneration system which enhances the utilization efficiency of synthetic energy by reducing the peak of the power demand arising by operating an air conditioner, utilizing the exhaust air at high temperature discharged from a dispersed power source. SOLUTION: In the exhaust heat utilization type cogeneration system consisting of a heat source, a desiccant air conditioner 2, and a cold blast utilizing facility, the desiccant air conditioner 2 is composed of at least a desiccant appliance 3 and a humidistat 5, and the heat source and the desiccant air conditioner 2, and the desiccant air conditioner and the cold blast utilizing facility are coupled severally with each other by fluid passages, and this cogeneration system can heat and reproduce the desiccant material damped within the desiccant appliance, by sending the exhaust gas at high temperature generated in the heat source to the desiccant appliance 3, and makes the damp air from the cold blast utilizing facility dry air by the desiccant material, and passes this dry air through the humidistat 5 thereby regulating the humidity to make cold blast, and supplies this cold blast to the utilizing facility.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste heat utilization type cogeneration system. More specifically, it is composed of a heat source, a desiccant air conditioner, and a utilization facility (air conditioning space). In particular, for the purpose of heating and regenerating desiccant units, a combination of directly using high-temperature exhaust gas (exhaust heat) from a heat source, The present invention relates to a cogeneration system utilizing waste heat for producing (cool air).

[0002]

2. Description of the Related Art In recent years, since the summertime in Japan is hot and humid, air conditioners have been widely used to provide a comfortable living environment for consumers, and the demand for electric power has been increasing. Power companies must rely on large-capacity power generation and long-distance transmission to respond to this power demand, but they have the disadvantage of high investment. Except when demand is high, it is a so-called monogeneration, and the efficiency of energy use is not high. In mono generation,
In many cases, half of the energy of fuel is released to the atmosphere or ocean as waste heat without being used.

Conventionally, a refrigerant compression type air-conditioning system using electric power has used fluorocarbon gas. However, since the problem of destruction of the ozone layer has become apparent, the use of fluorocarbon gas has been banned and future development is expected. There is no situation. In addition, the air-conditioning system using electric power cannot be expected to undergo dramatic development in the future due to problems such as long-distance power transmission and generation of carbon dioxide when generating power by thermal power. Furthermore, the time period during which the air conditioner is operated is concentrated, for example, during the daytime in summer, and the power demand reaches a peak, and electric power companies are struggling to respond to the power demand during this peak. is there.

In recent years, instead of the large-capacity generator, an on-site distributed power supply having a relatively small power generation capacity, such as a micro gas turbine or a fuel cell, has been developed and partially put into practical use. These distributed power sources are characterized by relatively high power generation efficiency despite their small occupied area and low cost equipment. Some or all of the power purchased from power companies (power purchase) has come to rely on distributed power sources. These on-site distributed power supplies
In facilities such as hotels, department stores, hospitals, convenience stores, various halls, etc., it is highly useful as a cogeneration system that can supply both electricity and waste heat,
By using it together with power purchase, the overall energy efficiency can be improved. However, conventionally, the utilization range of the exhaust heat supplied from these generation systems is limited to hot water supply and heating, so that there is a drawback that year-round utilization efficiency is not improved.

[0005]

Under such circumstances, the present inventors have found that there is no need to construct a new large-scale power generator, generate no carbon dioxide, and use solar power or on-site distributed power sources. As a result of intensive studies to provide a technique for effectively using high-temperature exhaust gas (exhaust heat), the present invention has been completed. That is, the objects of the present invention are as follows. 1. To provide a cogeneration system utilizing waste heat, which uses cold heat (cool air) using the heat from solar heat or distributed power sources as a heat source. 2. To provide a cogeneration system utilizing waste heat that can reduce peak power demand when an air conditioner is operating by generating cool air (cool air) using solar heat or waste heat from a distributed power supply as a heat source.

[0006]

In order to solve the above-mentioned problems, according to the present invention, in a waste heat utilization type cogeneration system comprising a heat source, a desiccant air conditioner and a cool air utilization facility, the desiccant air conditioner has at least a desiccant device. The heat source and the desiccant air conditioner are connected by a fluid passage, and
The use facility and the desiccant air conditioner are connected by a fluid passage, and the high-temperature exhaust gas generated by the heat source is sent to the desiccant air conditioner to heat and regenerate the wet desiccant material in the desiccant unit, and the wet circulation from the use facility Exhaust heat, characterized in that the air is passed through a desiccant to make dry air, the dry air is passed through a humidifier and humidified to make cool air, and the cool air can be supplied to utilization facilities. Provide a user-friendly cogeneration system.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
An exhaust heat utilization type cogeneration system according to the present invention includes a heat source, a desiccant air conditioner, and a facility (air conditioning space) for using cool air. In the present invention, the heat source is mainly a micro gas turbine, a gas turbine,
High-temperature exhaust gas (exhaust heat) generated when power is generated by an on-site distributed power source with the output of a diesel engine, gas engine, fuel cell, heat pump, waste power generation facility, or the like. In addition to these, the heat source is high-temperature exhaust gas discharged from various types of factories such as solar heat, steelworks, petrochemical plants, and cement plants, gas from waste incineration equipment, and combustion equipment for heavy oil and waste. High-temperature exhaust gas from these heat sources is used in a desiccant air conditioner described later as a heat source for heating circulating air and a heat source for heating and regenerating a desiccant material disposed in a desiccant device described later.
These heat sources may be a single type, a single type, a plurality of types, or a combination of two or more types.

A micro gas turbine as a heat source has three
It is a typical equipment of an on-site distributed power supply with a small output of about 0 kW. It is a device that burns various fuels such as city gas, propane gas, kerosene, and light oil and rotates the turbine to generate power. Approximately 25% is used as power generation output, and about 50% of the high-temperature exhaust heat discharged 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 conventionally used for hot water supply, heating, and the like, equivalent to 50% or more of fuel is effectively used as a heat source of cold air.

A fuel cell as a heat source is a power generation system that converts chemical energy such as hydrogen into electric energy by applying an electrochemical power generation principle. 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. May be of any type as long as a heat source of 100 ° C. or higher can be obtained. 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 the above (a) depends on the type of raw fuel (natural gas, LPG, methanol, naphtha, light oil, etc.), but is 170 to 210 ° C., so high-temperature exhaust heat is to be used. .

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, examples of the heat source include high-temperature exhaust gas discharged from various factories such as steelworks, petrochemical plants, and cement plants, and high-temperature exhaust gas discharged from waste incineration equipment.

[0011] The high-temperature exhaust gas as a heat source is released into the atmosphere after passing through the desiccant unit. However, when the gas temperature is sufficiently high even after passing through the desiccant unit, other heat removal is performed. It can be taken out as hot water or hot air by a vessel (heat exchanger) and used for other purposes.

The desiccant air conditioner in the waste heat utilizing cogeneration system according to the present invention comprises at least a desiccant device and a humidifier (humidifier). The desiccant unit has a desiccant material disposed therein, and after circulating in a utilization facility described later, dries the wet air returned to the desiccant air conditioner. The humid air returned from the utilization facility has a temperature of about 25 to 30 ° C. and a relative humidity of about 60 to 80%. In the desiccant air conditioner, a heat remover (heat exchanger) can be arranged between the desiccant device and the humidity controller. This heat remover functions to cool the dry air that has passed through the desiccant device to an appropriate temperature and guide the dry air to the humidity controller.

The desiccant unit is (1) a pellet-shaped desiccant material to be described later is disposed between plates of a plate-type heat exchanger, and (2) a honeycomb-shaped desiccant is described between plates of a plate-type heat exchanger. (3) Between the plates of the plate-type heat exchanger, a honeycomb-shaped material combining glass fibers with a desiccant material is arranged, (4) above (1) to (3) , And the like. When the desiccant device, the plate of the plate-type heat exchanger is configured by honeycomb, (a) portion to be filled with desiccant material,
The part (b) through which outside air passes is preferably arranged alternately.

[0014] Humid air having a temperature of about 25 to 30 ° C and a relative humidity of about 60 to 80% is introduced into the desiccant device having such a structure and circulated from the utilization facility.
Dry air having a temperature of about 55 ° C. and a relative humidity of about 5 to 25%. Since the desiccant material disposed in the desiccant device absorbs moisture from the humid air and the dehumidifying ability decreases with time, high-temperature exhaust gas (exhaust heat) from a heat source, for example, 100 to 25 is used.
By introducing the exhaust gas at 0 ° C. between the plates, the absorbed moisture can be dehumidified and dried, and the desiccant material can be regenerated.

The desiccant device absorbs the moisture of the humid air introduced from the facility back into the dry air by absorbing moisture of the desiccant material disposed therein, and introduces a high-temperature exhaust gas to remove the moisture of the desiccant material absorbed. Functions to dehumidify and dry. Any of the following methods can be used to introduce two types of gases having different properties into the desiccant device. (1) The plate-type desiccant unit is divided into two parts, wet air is introduced into one section, high-temperature exhaust gas is introduced into the other section, and the desiccant apparatus is rotated at regular operation intervals. Switch the entrance of
Method of alternately introducing two types of gases, (2) Method of disposing the desiccant unit as a fixed type without dividing into two parts, arranging two sets or three sets in parallel, and switching the gas to be introduced into each set at a fixed operation interval .

If the air circulated in the desiccant air conditioner is limited to only the humid air returned from the facility, the proportion of carbon dioxide contained in the air circulated to the facility gradually increases. For this reason, it is preferable that a part of the circulating air returned from the utilization facility to be introduced into the desiccant device is appropriately released to the outside air, and an amount of air corresponding to the released amount is taken in from the outside air. Also, after introducing high-temperature exhaust gas into the desiccant device to dehumidify and dry the desiccant material,
Normally, since the temperature of the desiccant material is overheated, it is preferable to introduce outside air and cool to an appropriate temperature before introducing humid air from the utilization facility.

The desiccant material to be placed in the desiccant device is excellent in moisture absorption / dehumidification / drying characteristics, can stably transfer heat, can be used repeatedly, and needs to have a long life. . According to the experiments of the present inventors, a compound having a maximum moisture absorption (adsorption) amount of 15% by weight or more at room temperature and a relative humidity of 80% and having a large number of small pores on its surface is porous. Was found to be preferable. If the maximum moisture absorption (adsorption) amount is less than 15% by weight, the moisture absorption properties are inferior, which is not preferable.

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 properties, and Na-type. Zeolite, Ca
Zeolites such as zeolite and Mg zeolite,
Aluminum oxide (Al ₂ O ₃ ), magnesium oxide (M
oxides such as gO) and clay minerals such as mordenite and allophane. The desiccant material is not limited to the examples as long as it has the above-mentioned surface moisture absorption characteristics. These may be one kind or a combination of two or more kinds.

In order to make these desiccant materials highly functional,
It is possible to increase the surface area by making the film thinner or porous, and to promote the moisture absorption / dehumidification behavior of moisture by exchanging cations or anions or increasing the surface area. The desiccant material is mainly used in the form of powder, pellets or honeycomb structure, and is disposed in the space of the desiccant device. It is preferable that the powdery material is combined with a glass fiber matrix to form a honeycomb structure and disposed between the plates of the plate-type heat exchanger, and the pellet-like material is filled in the space between the plates of the plate-type heat exchanger.・ It can be placed.

The desiccant device can be provided with a heat removal function by alternately arranging the portion (a) filled with the desiccant material and the portion (b) through which outside air passes. (a) part and (b)
By alternately arranging the part and the part, the moisture absorption heat generated by the desiccant material absorbing moisture when passing the humid air through the part (a), and the outside air and water in the part (b) are opposite to the humid air. (Countercurrent) to remove heat and cool to an appropriate temperature.

In the desiccant air conditioner, a humidifier (humidifier) is disposed after the desiccant device, and is connected by a fluid passage. A heat sink is placed between the desiccant device and the humidity controller, and if the desiccant material becomes hot due to moisture absorption when it absorbs moisture from the humid air, it will be adjusted to the appropriate temperature by the heat sink. Is preferred. In a humidifier, the dry air is evaporated by bringing the dry air into direct contact with water, such as by spraying moisture into the dry air in a mist form. Cool air at a temperature of about 15 to 28 ° C. and a relative humidity of about 40 to 100% is circulated and supplied to utilization facilities through a fluid passage.

In the present invention, the facility (air-conditioned space) for using cool air refers to a facility that can utilize cool air for cooling or air conditioning in a clean room. In particular,
Various halls such as hospitals, public halls, libraries, and 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 games Sites, various factories, various commercial facilities, and the like.

[0023]

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 diagram showing an example of a waste heat utilization type cogeneration system according to the present invention.
Is a schematic diagram of an example showing a change in the state of the temperature and humidity of the air in the desiccant air conditioner. FIG. 3 is a diagram showing a state in which a waste heat utilization type cogeneration system is operated in a large facility.
5 is a schematic diagram illustrating a relationship between a power load and an air conditioning operation.

In FIG. 1, reference numeral 1 denotes a micro gas turbine (a micro gas turbine manufactured by Takuma, type: TCP3)
0, a power generation output of 28 kW), and is an on-site type distributed power supply. The demand power consumed by the department store 6, that is, for lighting, in-building broadcasting, elevator operation, escalator operation, air conditioner operation, etc. is in a steady state. In the case of (1), power is purchased, but during the time period when the air conditioner is fully operated, the micro gas turbine 1 is operated to generate power.
High-temperature exhaust gas (about 250 ° C.) generated by operating the micro gas turbine 1 is introduced into the desiccant air conditioner 2. This desiccant air conditioner 2
It is a cube of 0 mm × 700 mm × 700 mm, divided into 15 stages by a plate, and is constituted by a desiccant device 3, a heat remover 4 and a humidity controller 5 having a heat removal function.
In FIG. 1, a heat remover 4 is provided between the desiccant device 3 and the humidity controller 5.
Although the example in which was installed was shown, as described above, this heat remover 4 may not be installed in some cases.

When the moist air having a temperature of about 30 ° C. and a relative humidity of about 80% from the department store 6 introduced into the desiccant unit 3 having a heat removal function passes through the desiccant unit 3, the humid air enters the desiccant unit 3 in multiple stages. Moisture is absorbed and dehumidified by a desiccant material (zeolite with a maximum moisture absorption of 15% by weight at room temperature and a relative humidity of 80%) placed on a plate placed in the air, and the air is dried and absorbed. By heat, the temperature is about 4
Dry air at 0 ° C. and a relative humidity of about 10% is used. The heat obtained by the desiccant device 3 can be used as hot water or hot air for other uses.

In the humidity control chamber 5, the water is evaporated by a method such as spraying water into the dry air in the form of a mist, and the dry air from the heat remover 4 is cooled to a low temperature by the latent heat of evaporation of the water. It is supplied as cold air at 18 ° C. and a relative humidity of 100% to various places in the department store.

As the air conditioning is continued by the desiccant air conditioner 2, the desiccant material (zeolite) disposed in the desiccant unit 3 absorbs moisture, and the moisture absorbing ability is reduced.
In order to regenerate the desiccant material by dehumidifying and drying it, the path of the gas introduced into the desiccant device 3 is switched, and the high-temperature exhaust gas (discharge heat) of about 250 ° C. from the micro gas turbine 1 is supplied to the desiccant device 3. Introduced into the part (b).
The direction of introduction of the exhaust gas at this time is opposite to the direction of the humid air (countercurrent). As described above, the high-temperature exhaust gas is introduced into the portion (b) of the desiccant device 3 so that the desiccant material in the desiccant device 3 is heated, dehumidified, dried, and regenerated. The high-temperature exhaust gas introduced into the desiccant unit 3 may be discarded into the atmosphere. If the temperature is still sufficiently high, the heat is exchanged with another heat exchanger to produce hot water or hot air, and hot water or hot air is used. Can be used for other purposes.

FIG. 2 is a schematic diagram showing an example of a change in temperature and humidity when circulating air is passed through the desiccant air conditioner. For example, circulating air having a temperature of 30 ° C. and a relative humidity of about 80% When (see point a) is passed through the desiccant device, the circulating air is dehumidified in the desiccant device, and the heat generated by the heat of moisture absorbed by the desiccant material is removed by the heat remover disposed after the desiccant device, At the outlet of the heat remover, the temperature is 30 ° C. and the relative humidity is about 5% as dry air (see point b). When the water is evaporated and humidified by a method such as spraying the mist into the dry air,
The temperature can be about 21 ° C. (see point c) and the relative humidity can be about 80%.

FIG. 3 is a diagram showing the relationship between the air-conditioning operation and the power load when the waste heat utilization type cogeneration system 1 is operated in a large facility. The vertical axis represents the power load, and the horizontal axis represents time. is there. In FIG. 3, during the period from 13:00 to 16:00 when the outside air temperature rises, the temperature of each place in the department store 6 also rises. Is operated, and the desiccant air conditioner 2 is operated by the high-temperature exhaust gas to perform an air-conditioning operation for dehumidifying, so that the power purchase of the portion indicated by 7 in FIG. 3 can be reduced. Micro gas turbine 1
As shown in FIG. 1, a plurality of can be installed.

[0031]

The present invention has been described in detail above, and has the following particularly advantageous effects, and its industrial utility value is extremely large. 1. The exhaust heat utilization type cogeneration system according to the present invention is integrated with a micro gas turbine generator, a fuel cell, or the like, thereby effectively utilizing the high-temperature exhaust gas (exhaust heat) to generate cool air. Because it can be manufactured,
It is effective as an energy-saving technology, and is extremely effective as a technology for reducing carbon dioxide emissions, effectively using fossil fuels, and preventing global warming. 2. The exhaust heat utilization type cogeneration system according to the present invention is capable of producing cold air by effectively utilizing the high temperature exhaust gas by being integrated into a micro gas turbine generator, a fuel cell, etc., thereby greatly increasing the energy utilization efficiency. Can be improved. 3. Since the exhaust heat utilization type cogeneration system according to the present invention makes effective use of high temperature exhaust gas to produce cool air,
The utilization form of exhaust heat is not limited to hot water supply, heating, and the like as in the related art. 4. The exhaust heat utilization type cogeneration system according to the present invention operates the air conditioner because the small generator is operated to reduce the amount of electricity purchased, and at the same time, the air conditioner is operated by effectively using the high-temperature exhaust gas. This can reduce the peak of the power demand caused by this and improve the total energy efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a heat recovery utilization type cogeneration system of the present invention.

FIG. 2 is a schematic diagram illustrating an example of a change in state of temperature and humidity of air in a desiccant air conditioner.

FIG. 3 is a schematic diagram showing a relationship between an electric power load and an air-conditioning operation when a waste heat utilization type cogeneration system is operated in a large facility.

[Explanation of symbols]

1: Micro gas turbine 2: Desiccant air conditioner 3: Desiccant unit 4: Heat sink 5: Humidifier 6: Department store 7: This is a part that can reduce power purchase by operating the micro gas turbine.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02G 5/04 F02G 5/04 H F25B 27/02 F25B 27/02 R H01M 8/00 H01M 8/00 Z (72) Inventor Nobuo Yamada 5-34-6 Shiba, Minato-ku, Tokyo Mitsubishi Chemical Engineering F-term (reference) 3G081 BA11 BC13 DA22 3L053 BA10 BC03 BC06 BC08 4D052 AA08 BA03 DA03 DA08 DB02 HA01 HA02 HA03 HA06

Claims (7)

[Claims] 1. A waste heat utilization type cogeneration system comprising a heat source, a desiccant air conditioner and a cool air utilization facility, wherein the desiccant air conditioner comprises at least a desiccant device and a humidity controller. , A fluid passage, and the utilization facility and the desiccant air conditioner are connected by a fluid passage, the high-temperature exhaust gas generated by the heat source is sent to the desiccant air conditioner, and the wet desiccant material in the desiccant device is Heat and regenerate, and the wet circulating air from the utilization facility is passed through a desiccant to make dry air, and the dry air is passed through a humidifier to humidify and cool the air, and this cold air can be supplied to the utilization facility. A waste heat utilization type cogeneration system characterized by being performed. 2. The waste heat utilizing cogeneration system according to claim 1, wherein a heat rejector is disposed between the desiccant device and the humidity controller. 3. The waste heat utilization type cogeneration system according to claim 1, wherein the desiccant device has a plate type heat exchanger structure and also has a heat removal function. 4. The desiccant material has a room temperature and a relative humidity of 80%.
The exhaust heat utilization type cogeneration system according to any one of claims 1 to 3, wherein the compound is selected from compounds having a maximum moisture absorption of 15% by weight or more under the following conditions. 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. Waste heat cogeneration system. 6. The heat source is a high-temperature exhaust gas generated in an on-site distributed power generation facility such as a micro gas turbine, a gas engine, a gas turbine, a diesel engine, a fuel cell, a heat pump, and an incinerator power generation facility. An exhaust heat utilization type cogeneration system according to any one of claims 1 to 5. 7. Use facilities include hospitals, public halls, libraries, culture halls, schools, kindergartens, gymnasiums, nursing homes, apartment houses, office buildings, hotels, restaurants, department stores, supermarkets, convenience stores, pachinko playgrounds, and various factories. The exhaust heat utilization type cogeneration system according to any one of claims 1 to 6, which is a commercial facility or the like.