SA08290039B1 - Dehumidifying Cooling Device For District Heating - Google Patents

Abstract

Abstract The invention relates to the disclosure of a moisture-reducing cooling device for dehumidifying for district heating, which includes, a box that includes a partition to divide the interior of the case into a wet channel and a dry channel, and a rotatable sensible heat exchanger for exchanging the heat of outside air in the wet duct with circulated air in the dry duct, heating coil to raise the temperature of the outside air, rotary dehumidifier wheel for adsorption and removal of moisture contained in circulating air in the dry duct and is recovered by evaporation of the adsorbed moisture, cooler regenerative-evaporative cooler to cool circulated air in a dry duct. In this way, the method can implement the air cooling process using hot air supplied by district heating systems and gas or oil boilers installed in individual homes, thus achieving a miniature size of the method by implementing the cooling process under atmospheric pressure and production costs low thanks to the simplified system format. Figure (1).

Description

Dehumidifying cooling device for district heating Full Description BACKGROUND The present invention relates to a dehumidifying cooling device for district heating; Very specifically, a dehumidifying cooling device for district heating that can perform an air cooling operation using water supplied by district heating systems on a large or small scale. Gas or oil boilers installed in individual homes. There is a widespread expectation that the current high oil price situation is not a temporary problem; And this is constantly confirmed and confirmed. And therefore; The major energy consuming countries in the world are increasingly making great efforts to secure stable energy resources. And by activating the 0 Tokyo Protocol that deals with the reduction in discharge of ball “greenhouse gas” in order to avoid global warming; It is expected that international pressure will be strengthened regarding the specific use of fossil energy and the criterion of energy efficiency...etc. According to the published energy report; The amount of energy consumed in 05 domestic and business fields in Korea in ¥ You was 00 million YAAA equivalent

b petroleum per ton in dnd, and that occupies 775.7 of the total national consumption energy. This percentage also matches 713 on the basis of electricity (Lbasis of electricity) and for the last four years; The energy consumption of households and businesses shows an annual rate of increase with an average of JOLT and where electricity consumption shows an annual rate of increase with an average of VY and accordingly; It is recognized that there is a rapid increase in electricity consumption in particular. estimation based on the change in monthly energy consumption of residential buildings and a sample survey leading to non-residential buildings as the locus of energy control; The analysis is that 7,500 of the energy consumption of residential buildings and 747 of the energy consumption of business buildings are accustomed to air conditioning. In conclusion; The energy consumption of buildings and the energy required for air conditioning make up 00,019 of the total national energy consumption in Korea. Accordingly; To ensure the efficient use of energy and the continuous growth of the energy industry while adhering to the relevant international agreements; It is necessary to improve the efficient use of energy for air conditioning in homes and business areas 0 From the point of view mentioned; There is an activation of the so-called total energy industry in which, specifically, all thermal energy and electricity VO generated from power generation facilities stationed at a specific location are supplied to improve the effective use of energy in homes and business areas to a group of users in Residential areas and business areas. It is noteworthy that the collective energy industry uses waste heat during power generation as a heating source for a specific space and hot water heating. Y AAA

aml and energy efficient; But also to improve the aerodynamics by a ratio of Fr to approximately 0 78 thanks to

Reduction usage of fuel and discharges as a whole industry capable of dealing with

International environmental restrictions related to this ally include climate change agreement...etc. And in religion

Positive Rating in Korea Approximately VY 1 million share the benefits of district heating in a year

© 007 and precisely alg 7780 of the energy supplied by power generation and heat

Combined heat and power generation. Korea has a plan to expand the propagation range of district heating to 7 million families by the year Yds.

And in combined heat and power generation, “that is, co-generation.”

0; The thermoelectric generation ratio is fixed at ?:co and therefore it is important to maintain

0 on the electricity-to-heat ratio at an appropriate level to increase the impact of the overall energy industry. F can

Korea achieves the aforementioned birth rate in winter; But Korea in the summer suffers from pregnancy

Increased electricity load for air cooling and no heat load

operation rate to a large extent. As a result; The operating rate of the district heating heat load decreases

of distinct heating in the summer to less than LV, which leads to a deterioration in economic efficiency

A deterioration in the economical efficiency of cogeneration, and indeed, did not

Results for birth appear between June and September in the year YoY

And to improve the operation rate of collective-energy generation facilities

Sufficiently utilizing the effects generation facilities

Detecting the demand for heat in the summer is necessary. Specifically, the growth and spread of sourcing technology

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The cooling card that necessarily uses energy heating facilities is a distinct heating necessary, and in one of the examples of the previously mentioned cooling energy supply technology, an absorption chiller is installed for a large-scale Jie facility building receiver. Etc. so that the chiller carries out a central cooling operation using energy coming from the district heating facilities. flowing in a pipe using heat generated during the 32d evaporation liquid-phase cooling and sale condensation gas-phase cooling | 0 evaporated soley used. General description of the invention Technical problem: However; Although the various researches and developments to improve the aforementioned performance; The absorption chiller has a limit in improving | As a result of the low temperature of the heating source. \o In addition; Absorption chiller 1 has a high water return temperature and is uneconomical as it cannot use an ele that has a temperature of 760°C or less and suffers from a small difference between the temperature of the water being supplied and the temperature of the water being returned. Yaaa

And when an absorption chiller is installed in an apartment...etc, which occupies most of the district heating part to operate central cooling ¢, there is a problem that cold water pipes must be additionally installed, regardless of the hot water supply pipes and : -water supply pipes 0 and thus the current extraction is done due to the previous problems; The object of the present invention is to provide a moisture-reducing cooling device for district heating dehumidifying for district 8 that can perform air-cooling work using hot water supplied by district heating systems on a large or small scale and oil boilers gas or oil boilers installed in individual homes; Thus, a reduction in the size of the medium is achieved by implementing operation under atmospheric pressure and with reduced production costs due to the form of the simplified system. The technical solution according to the appearance of the invention ». Cooling device dehumidifying for district heating Dehumidifying for district heating: A box that includes a barrier Yo 08 to divide the inner part of the box Divide the interior of the case into a wet channel and a dry channel + and is supplied The wet duct at one end has an external air suction hole to introduce outside air into the wet duct; At the other end there is an exhaust hole for discharging the outside air »+ and a dry duct is provided; at one of its extremities; With a YAAA suction hole

Circulating air to enter the circulating air from the conditioning space into the dry duct; at the other end with an air supply hole to supply cool air to the air-conditioning compartment; a sensible heat exchanger Jae to circulate around the diaphragm and exchange the heat of the introduced outside air into the wet duct through the outside air “suction hole©” and by introducing the circulating air into the dry duct; and a heating coil Installed in the wet duct at a position between the rear end of the sensible heat exchanger and the exhaust hole and serves to raise the temperature of the outside air passing through the wet duct by using the heat of hot water entered into the heating coil coil and AREA dehumidifying wheel to rotate around the baffle at a position behind 0 of the heating coil and serve to adsorb and remove the moisture contained in the circulating air within the dry duct; The moisture-reducing wheel is recovered by evaporation of the adsorbed moisture so that the evaporated moisture is supplied to the high-temperature outside air in the wet duct; An evaporative regenerative cooler installed in the dry duct at a position between the circulated air supply hole and the sensible heat exchanger and serves to cool the circulated air in the dry duct whose moisture is 05 reduced to high temperature dry air by means of a wheel dehumidifying Jully wheel Heat is exchanged and cooled by the felt heat exchanger ¢ and the cooled air sill is conveyed to the air supply hole of the box. preferably; The method also includes: YAAA

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A direct evaporative cooler installed in the dry duct at a position in front of the regenerative-evaporative cooler + and the direct-evaporative cooler that performs a secondary cooling operation of the circulating air exhausted from the regenerative evaporative cooler.

© and preferably; The device also includes: a first filter installed between the outside air suction hole and the sensible heat exchanger and works on all the impurities contained in the outside air and an exhaust blower installed between the dehumidification wheel and the exhaust hole alll and discharging the outside air forcefully from the wet duct through the exhaust hole;

0 where the first filter and the exhaust blower are installed in the wet duct. preferably; The facility also includes: a second filter fitted between the circulating air intake hole and the dehumidifying wheel and acting on “impurities contained in the circulating air” and an air supply blower fitted between the dehumidifying wheel and the sensible heat exchanger and functioning to drain the strongly cooled circulating air from the dry duct through Air supply hole where yo second filter and air supply blower are installed in the dry duct.

Preferably, the box is also provided with a hole for the cooler's exhaust to discharge the high-temperature air generated during the regenerative-evaporative cooler for the secondary cooling operation Lal. Preferably, the amount of high-temperature air discharged through the cooler exhaust hole is 770 of the total circulating air. Yaaa |

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J » heating coil The hot water that is entered is transferred to the heating coil (Jamia) and in the form of heating; a cogeneration plant, any one selected from among the cogeneration units, a gas turbine, a small gas engine, and a gas engine Small micro-turbine, small turbine, boiler .0il boiler, oil boiler, gas boiler jell, small gas turbine, small air, ae hall, and in detail, the circulating air is mixed through the suction hole ©

JOY with a predetermined mixing ratio of outside air Beneficial effects: dehumidifying for district Moisture reducer for energy heating cooling device According to a cooling medium, the air cooling process can be performed using Jal having the aforementioned form lly of the present invention heating hot water supplied by district heating systems on a large or small scale or gas or oil boilers installed in individual houses. Accordingly; The present invention has an effect on achieving a miniaturized size of the medium by implementing a chip and reducing production costs due to the atmospheric pressure form of the simplified system for cooling under atmospheric pressure. The current from las is clearly done The following detailed description taken in conjunction with the accompanying graphics; in which:

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= (1) JSS: A view showing the figure of the Aly cooling dehumidifying device for district heating of the present invention; : Figure (7): A view showing the air flow in the dehumidifying device for district heating of the present invention; and © fig. With reference to the accompanying schematics.0 In the following description of the present invention, the detailed description of the known functions and forms included herein are omitted when they also render the technical subject matter of the present invention unclear.The terms used in the following description are also considered to be specific conventions that take into account the functions that are Obtained according to the present invention The definitions of these terms should be determined based on the total content of these specifications Dus it can be changed according to the choice of the user or the operator or the normal application Figure (1) is a view showing the shape of a cooling device Dehumidifying for district heating YAAA

11 — According to the present invention. Referring to Figure (1), the dehumidifying cooling device (Ver) according to the present invention includes the case (0), first filter (0) and the sensible heat exchanger (V+) sensible heat exchanger, heating coil (VE4)©, dehumidifying wheel (+12), exhaust blower (V0), second filter (VV) second filter, air supply blower (YA+) air supply blower, regenerative-evaporative cooler (050) and direct evaporative cooler (001) dircct-evaporative cooler. The box (111) is made of metallic material and is It has the shape of a rectangular box 0, and the box (00) is installed with a barrier (115) partition to divide the interior of the case (VV +) divide the interior of the case into a wet channel (11) and a dry channel 0 (111) dry channel, and the box (111) has a bail hole (VY) outside air suction hole located at one end of the wet Jay (111) channel Introducing outside air into the (VI) ) wet channel 05 and an exhaust hole (VVY) located at the other end of the wet channel (111) for draining outside air discharging the outside air The box (011) also has a hole for circulating air suction (VV) air suction hole located at one of the ends of the dry channel (111) end of the dry channel to enter air from the air conditioning space conditioning space to the dry duct (110) and an air supply hole (YVV) at the other end of the dry duct (115) to supply cool air to the conditioning space. Dry duct YAAA is also supplied

? secondary cooling operation which is described hereinafter.circulated air introduced into the box (111) through a circulated air suction hole (Y V1) is mixed with air outside air at a rate of ov?to maintain the presence of the (VV) interior of the case at ds atmospheric pressure, and the first filter (VY +) first filter is placed In the wet duct (111) of the box (111) at a position between the outside air suction hole (VY) outside air suction hole and the Sus (VY) sensible heat exchanger 0 using the first filter ( 01) in removing impurities and unpleasant odors contained in ventilated outdoor air. JS is preferred; the first filter (VY) is an antibacterial filter; it is easily detachable from the box (111). And the sensible heat exchanger (1Y+) sensible heat exchanger has a rotating shaft (VY) 0 mounted in the same direction as the partition (119) Jie and takes the shape of a cylinder to rotate around the shaft (11) inside the wet channel (111) inside the wet channel and the dry channel (010) of the box (111). Through the outside air suction hole (1 ¥) air suction hole with the introduction of circulated air into the dry duct (0) (115). home addressing the YAAA board

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VW) etc. The felt heat exchanger ... aluminum plate Jie whose moisture is reduced circulated air performs a primary heat exchange process to lower the temperature of the circulating air described hereafter (Vo) 46000101108 wheel for rotation of an additional motor and belt (not shown) are provided for rotation of the sensible heat exchanger © (YY) the sensible heat exchanger of the box 1) 1) wet channel in Wet duct (VE) heating coil The heater coil and exhaust hole (VY) are placed at barrier 0 between the rear end of the felt heat exchanger (111) to raise the outside air temperature (VE) and the heater coil is used (11 Y) exhaust hole passing through the wet duct (001) using the heat of hot water inlet to outside air 0 from any one selected among the cogeneration units; and boiler (00) heating coil heating coil

Te heating, small terrine, gas boiler, and oil boiler, and it has a temperature within a range from 071 to (YoV) rotating shaft (Vo +) dehumidifying wheel, and it has a wheel for reducing humidity and takes the form of A disk to rotate around a column (119) partition Jie installed in the same direction 0 and the channel (111) inside the wet channel Jala (191) rotating shaft rotation dehumidifying wheel and the wheel is placed Dehumidifying (VV+) dry (110) for the box and adsorbing and dehumidifying included in the (VE) heating coil behind the heating coil (Vou) inside the dry duct (110) and dehumidifying wheel circulated circulating air

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— NE by evaporating the adsorbed moisture so that the moisture is supplied to the air (151) dehumidifying wheel cide the wet channel Jala wet channel with high temperature outside the outside air in the form of a disc in the form of (Vor) dehumidifying wheel and takes Dehumidifying wheel 0 (111) or similar zeolite or silica gel silica gel Jie honeycomb contains adsorbent Adsorption The moisture contained in the circulating air by dry adsorption method. Additional motor provided © (151). A belt (not shown) for rotating the dehumidifier wheel (11) for the box (1111) in the wet duct (10) exhaust blower and exhaust blower and universal hole (10+) are installed dehumidifying wheel at a position between the forcibly dehumidifying wheel from the duct discharging the outside air and use it to drain the outside air (11”) into hole (111) 0 (011) of the box (M10) in The dry stream (OV) 5606000 filter The second filter and the dehumidifying wheel (111) circulated air are installed at a position between the circulating air suction hole and used to remove impurities and unpleasant odors contained in the air (001) dehumidifying wheel antibacterial filter for anti-bacterial Ble filter. Preferably, the second filter shall be (111) case. It shall be easily detachable from the box 05 in the dry duct (110) of the box (VA) air supply blower and the waffle supply blower shall be installed and used in (0901) dehumidifying wheel at a position in front of the dehumidifying wheel (011) with force from the dry duct (110) through the circulated air supply hole (17).

Yo _— — The (Ver) regenerative-evaporative cooler is installed in the dry duct (110) at a location between the (VV) circulated air supply hole and the sensible heat exchanger (AT) sensible heat exchanger If the moisture of the circulating air entering the dry duct (Vye) is reduced by the dehumidifying wheel (Vor) © to be changed into dry air of higher temperature and thus heat exchanged and cooled by the sensible heat exchanger (11 ); The temperature generated during cooling to the cooler exhaust hole is 0. (1 A) hole, and here is the amount of high-temperature air that is discharged through the cooler exhaust 0 fl (118) with a value of 7270 from Total circulating air The interior of the regenerative/evaporative cooler (190) is divided into a dry channel ila and a wet channel If a part of the air passing through the dry duct is transferred to the wet duct; The air is cooled as the water is evaporated by the high-temperature surface of the wet stream »; Thus, the heat is absorbed from the residual high-temperature air passing from 05 through the dry duct. Thus; The air passing through the dry duct can be cooled to the dew point warmness up to the fullest extent without an increase in humidity. The form of the regencrative-evaporative cooler (V4 +) regencrative-evaporative cooler is disclosed in Korean Patent No. 01735 and therefore; Its detailed description is omitted in this document. The direct-evaporative cooler (001) shall be installed in the dry duct (111) 0 of the box (111) at a position in front of the regenerative/evaporative cooler (190).

A 001 A direct evaporative (Y re) procedure involves a secondary cooling operation of the circulating air from the regenerative/evaporative cooler. (1150) The resulting air is supplied to the conditioning space through a hole Air supply “(YVY) air supply hole to box ‎(OY) The operation and effects of the zonal axl dehumidifying cooling device © of the present invention are described later in this document with reference to Figures-1) ¥) Figure (1) is a view showing the air flow in the moisture-reducing refrigerant for zonal heating according to the present invention; the figure (©) is a graph showing the temperature distribution of moist air used in the reduced-moisture refrigerant Dehumidifying cooling device. temperature and high humidity to the dry duct (10101) of box (00) through the circulating air suction hole (6) (VY) under operation air supply blower ans (VAY) passing through the second filter second filter (171)”_circulated air 0 inlet passes sequentially > through the dehumidifying wheel (VO) so that the moisture contained in the circulating air is removed by the adsorbent. The circulating dehumidifying air is heated by the adsorption heat generated by the surface of the dehumidifying wheel (Vor). The heat exchange of the resulting high-temperature and low-humidity circulating air with the outside air takes place in the wet duct (111) by means of the Agala sensible heat exchanger.

A (VY +) sensible heat exchanger, and thus the circulating air is changed to low-degree Shall air before it is introduced to the regenerative-evaporative cooler (+4) and if the circulating air is introduced to the cooler regenerative/evaporative (0091); the IF is discharged from the circulating air to the outside through the exhaust hole of the refrigerant (11 A).

° It is secondary to cooling the air & circulating which is fanned through the radiator | Regenerative/evaporative - (Va) while passing through a “(Y++) direct-evaporative cooler and thus supplied to the conditioning space through the air supply hole (1 VY) supply hole of the VY and the heat exchange process that takes place in the wet duct (111) is then explained.

0 High temperature and high humidity outside air is introduced into the wet duct (111) through the outside air suction hole (YY) outside air suction hole and passes through the first filter (VY) under operation Exhaust blower (130).Then the heat exchange of the filtered outside air with the circulated air in the dry duct (VY0) is carried out by means of the (VY'+) sensible heat exchanger so that the temperature of outside air temperature

outside air Yo . Thus; The outside air with the high temperature passes through the heating coil –(Y £ +) heating coil, and while passing through the heating coil (0), the temperature of the outside air is also raised by the hot water that It is supplied to the heating coil (1560). Hence, the air is Y AAA

YA = — outside which is transferred to the dehumidifying wheel (+10) a temperature that is too high. When the dehumidifying wheel (+12) rotates in Ala adsorbing moisture in it, the outside air vigorously evaporates its moisture during Passing through the dehumidifying wheel (100) and then draining out through the exhaust hole (11”). Through the aforementioned process, the surface of the dehumidifier wheel (100) is returned to the original alls; Restore its ability to reduce humidity Referring to Figures (7) and (TV) if in a dehumidifying device for district heating according to the invention Mall enters the circulating air 0 dark (1) circulated to the box “case” the circulating air (1) mixes with outside air (VY) outside air to produce mixed air (1) with high absolute temperature and humidity. Through the dehumidifying wheel, the mixed air ( ) is changed into air with high temperature and low absolute humidity (3). The heat exchange of air (7) with outside air (A) in the wet duct 0 is then passed through a sensible heat exchanger so that the heat exchanged air (4) Only a slight decrease in temperature. During successive passage through the “(Y4+) regenerative-evaporative cooler the air temperature is quickly reduced (4) to produce significantly cooled air (0) and during subsequent passage of air from Through the direct-evaporative cooler + the YAAA temperature is also reduced

= 9 — : air (2) slightly, but the absolute humidity of the air (9) rises; this results in cooling air (3). When the outside air passes the inlet (V) introduced outside air at the same time through the first filter « then the filtered air (A) has the same absolute temperature and humidity ie 5 as that of the air (V) and heat exchange takes place for the air (A ) with circulated air ( ) in the dry duct while passing through the sensible heat exchanger. The resulting heat exchanged air (9) is slightly raised in temperature but maintains the same absolute humidity (Jie That of air (8). In temperature, but it rises in absolute humidity in the path of passage through the dehumidifying wheel, thus changing it into low-temperature and high-humidity air (11). In an aa dehumidifying cooling device for district heating of the present invention the air supplied to the 05 air-conditioning interior is subjected to heat and moisture transfer by direct contact with the dehumidifying coolant. This has the effect of achieving excellent transmission efficiency and the production and supply of cooling air with a heating source for a low temperature of 10 m. In a different way than conventional adsorption media; This dehumidifying cooling device is effective Lad in Y AAA |

ddh _— the state of atmospheric pressure and has a simplified form; Leads to a significant reduction in manufacturing costs. industrial applicability as indicated by the foregoing description; The dehumidifying cooling device © of the present invention can be installed in residential buildings, business buildings, etc. using hot slo conveyed from district heating facilities; To use hot water as a source to cool the place. Although the preferred embodiments of the present invention are disclosed for illustrative purposes; Those skilled in this field will realize that multiple modifications, additions, and substitutions can be made to it without departing from the scope and essence of the invention. As disclosed in the accompanying claims.

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Claims (1)

Cov dehumidifying for cooling device cooling device =) 1 0 includes district heating Y wet partition als box includes F = ; The wet duct is provided at one end with a dry channel and a dry duct ¢ introducing outside air into for external air suction to introduce external air into the wet duct 0 for exhaust hole; At its other end, there is a hole for the exhaust, the wet channel 1, and the dry channel is provided.” at one of its extremities; by discharging the outside air conditioning space circulated air to introduce the circulating air into the dry duct; and at its other end with an air-supply hole for providing cool air to the air-conditioning compartment 4 0; External input VY to circulated air and by entering the circulating air ¢ outside air suction hole outside air 0 (all duct 4 for coil iS al— 10 and works exhaust hole and exhaust hole sensible heat exchanger The sensible heat dal no 7 passing through the moist duct outside air ha on an elevation 11 “heating coil by using the heat of hot water entered into the heating coil 08 partition formed to circulate around the baffle dehumidifying wheel - - 4 Als contained moisture adsorbs heating coil at position behind Yo heating coil inside dry duct; dehumidifying wheel circulated air is recovered into circulating air 71 Yaaa YY — a dehumidifying wheel YY by evaporating the adsorbed moisture so that the evaporated moisture is supplied to YY the high temperature outside air in the wet duct; YE regenerative-evaporative cooler installed in the dry channel Yo at a position between the circulated air supply hole 1 and the sensible heat exchanger and serves to cool the circulating air YV It is circulated in the dry stream; whose moisture is reduced to high YA temperature dry air by dehumidifying wheel thus; 4 The heat is exchanged and cooled by the sensible heat exchanger » and the cooled circulated air is transferred to the air supply hole of the box. 1 7?- device Alig according to claim (1) also includes: - a direct-evaporative cooler installed in the dry duct at a position in front of the regenerative-evaporative cooler » and the cooler The direct-evaporative cooler that performs a 43530 secondary cooling operation 2 of the circulating air from the regenerative-evaporative cooler ,. evaporative cooler 1: also includes: (1) according to the element of protection device device* - 1 outside air suction hole installed between the first filter Js filter - v and the heat exchanger Sensible heat exchanger and works to remove impurities contained 3 in the outside air; and 5 - Exhaust blower installed between the dehumidification wheel and the exhaust hole and works on YAAA dj i forcefully discharging the outside air from the wet duct through Vv the exhaust hole ¢ A - where the first filter and the exhaust blower are installed in the duct q wet. 1 ¢— The device according to Clause (1) also includes: - A second filter installed between the circulating air suction hole and the humidity reduction wheel 3 and works to remove impurities contained in the circulating air circulated air ¢ and - a supply air blower installed between the dehumidifying wheel and the sensible heat exchanger 2 and forcefully discharges the cooled circulated air from the dry duct 1 through the waffle air supply hole ¢ 7 where the second filter and the air supply blower are installed in + the dry duct. High Temperature Generated UB Regenerative Cooler ¥ and Evaporative Cooling Procedure for Secondary Cooling Operation 1 - Device according to Clause (25) wherein is the amount of high temperature air Y discharged from Through the 7700 cooler exhaust hole of the total circulated air ¥. Yaaa 1 for the means (a, device) of the protection element (1) where Ju is the hot water that is then entered into the Y heating coil from any one selected among the cogeneration plant 1 units ¢ heating boiler, micro-turbine ¢ small gas engine, small gas turbine, © gas boiler, drip-oil boiler 1 - A means according to Claim (1), whereby the circulated air ¥ is mixed through the circulated air suction hole with the outside air at a predetermined mixing ratio of 1 NOV 1 4- A means according to Claim (1), where the mixing ratio specified in advance for the circulating air to the outside air is 7:7. Yaaa