JP2009174831A - Air conditioning system and air conditioning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning system using a water medium for easily, inexpensively and stably conditioning air to be heated/cooled. <P>SOLUTION: The air conditioning system is provided for controlling a temperature in a constant temperature room while circulating hot water as heat medium. It comprises a first heat exchanger for heat exchange between air in the constant temperature room and the hot water, a second heat exchanger for cooling the hot water drained from the first heat exchanger in heat exchange with outside air, and a heating device for heating the hot water drained from the first heat exchanger. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a constant temperature room air conditioning system and an air conditioning method.

  Various systems that regulate the temperature of a temperature-controlled room are known. Typical examples include indoor heating and cooling, and air conditioning systems. However, in the case of temperature-controlled rooms used for industrial purposes, facilities are generally large, and many of them consume a large amount of energy such as electric power. For home air-conditioning systems, easy handling and downsizing of facilities are issues, but for industrial use, reduction of facility costs and energy costs are major issues.

  As an air conditioning system for an industrial temperature-controlled room, a heat pump type air conditioning system is well known as well as an indoor air conditioning system. FIG. 3 shows an example in which a heat pump type air conditioning system is used in a temperature-controlled room. In FIG. 3, an air conditioning system 101 is provided to cool or warm the temperature of the temperature-controlled room 2. The air-conditioning system 101 is a heat pump type refrigerator / heater that normally uses a refrigerant such as chlorofluorocarbon or ammonia.

  The air conditioning system 101 includes a first heat exchanger 104 for cooling or heating the air sucked from the temperature-controlled room 2, and a second heat intake or discharge from outside air into the refrigerant. A heat exchanger 107, a compressor 110 that compresses the refrigerant gas, and an expansion valve 111 that discharges the compressed and cooled refrigerant to the low pressure side are provided.

  A flow path that includes the compressor 110 and connects the first heat exchanger 104 and the second heat exchanger 107 is a refrigerant gas that is compressed by the compressor 110 by the operation of the flow path switching valves 112 and 113. Is compressed by the compressor 110 from the first heat exchanger 104 and transferred to the second heat exchanger 107, or is compressed by the compressor 110 from the second heat exchanger 107 to the first heat exchanger 104. Can be transported. Correspondingly, the expansion valve 111 is operated by operating the flow path switching valves 114 and 115 of the flow path including the expansion valve 111 and connecting the first heat exchanger 104 and the second heat exchanger 107. The refrigerant expanded in step 2 is moved from the second heat exchanger 107 to the first heat exchanger 104 through the expansion valve 111 or from the first heat exchanger 104 through the expansion valve 111. Or move in the direction of the heat exchanger 107. By doing so, the tube 105 of the first heat exchanger and the tube 108 of the second heat exchanger become a refrigerant evaporator or a refrigerant gas condenser, respectively.

  Specifically, when the air conditioning system 101 is in the cooling operation, the tube 105 of the first heat exchanger functions as an evaporator, and the evaporated refrigerant gas is guided to the compressor inlet 110a by the flow path switching valve 112, and Compressed and introduced into the tube 108 of the second heat exchanger via the flow path switching valve 113 from the compressor outlet 110b. Then, the compressed refrigerant gas is cooled and condensed by the second heat exchanger 107 to become a liquid refrigerant, and from the expansion valve side inlet / outlet 108b to the expansion valve inlet 111a through the expansion valve inlet 111a to the expansion valve 111. be introduced. The refrigerant introduced into the expansion valve 111 is depressurized by passing through the expansion valve 111, led to the tube 105 of the first heat exchanger via the flow path switching valve 114, and the tube 105 of the first heat exchanger. The refrigerant evaporates into refrigerant gas and is circulated from the compressor side inlet / outlet 105a to the compressor 110. At this time, the air in the first heat exchanger is cooled by the latent heat of the refrigerant gas. The cooled air is circulated to the temperature-controlled room 2 by the blower 106 to cool the temperature-controlled room 2.

  When the air conditioning system 101 is heated, the refrigerant circulation is reversed from that in the cooling operation. That is, in this case, the tube 108 of the second heat exchanger functions as an evaporator, and the evaporated refrigerant gas flows from the compressor side inlet / outlet 108a of the tube 108 of the second heat exchanger to the compressor inlet 110a by the flow path switching valve 113. , Compressed by the compressor 110, and introduced into the tube 105 of the first heat exchanger from the compressor outlet 110b via the flow path switching valve 112. Then, the compressed refrigerant gas dissipates heat in the first heat exchanger 104 and condenses to become a liquid refrigerant. At this time, the air in the first heat exchanger 104 is heated by the condensation heat of the refrigerant gas. The heated air is circulated to the temperature-controlled room 2 by the blower 106 and heats the temperature-controlled room 2. The condensed refrigerant is introduced into the expansion valve 111 from the expansion valve inlet / outlet port 105b side of the tube of the first heat exchanger through the expansion valve inlet port 111a by the flow path switching valve 114. The refrigerant introduced into the expansion valve 111 is depressurized by passing through the expansion valve 111, led to the tube 108 of the second heat exchanger via the flow path switching valve 115, and is then fanned by the second heat exchanger 107. Heated by the outside air introduced by 109, evaporates in the tube 108 of the second heat exchanger to become refrigerant gas, and is circulated from the compressor side inlet / outlet 108a to the compressor 110 via the flow path switching valve 113.

  In addition, several industrial air conditioning systems are known. For example, Patent Document 1 discloses an air conditioning system for adjusting the temperature of a plurality of spaces, which includes a hot water circulation line and a cold water circulation line, and performs air conditioning using respective heat exchange coils. Furthermore, energy consumption of hot water and cold water is optimized by a heat management system having a heat pump.

  The constant temperature device disclosed in Patent Document 2 is a device that adjusts the temperature of the liquid in the constant temperature bath. The constant temperature bath liquid is led to a heat exchange tank equipped with a heat exchange tube, and cold water is supplied to the heat exchange tank. Or this cold water is heated with a heater, and the temperature of the liquid in the thermostatic chamber passing through the heat exchange tube is controlled.

  Patent Document 3 discloses a cooling system in a semiconductor manufacturing facility. In this cooling system, low-temperature, medium-temperature, and high-temperature cooling water is prepared according to the control temperature of the object to be cooled, and the cooling efficiency is optimized by combining multiple cooling waters to cool multiple objects to be cooled. We are trying to make it. For cooling the cooling water, not only refrigerators but also cooling towers are used to optimize energy use and equipment costs.

Patent Document 4 discloses an invention of an air conditioning system in a natto manufacturing apparatus. In this invention, the temperature of the natto fermentation chamber is heated to 52 ° C. with a heater for fermentation, and when the fermentation is completed, the air in the natto fermentation chamber is heat-exchanged with warm water and cooled. The hot water for cooling is cooled and reused using a cooling tower.
JP 2005-501213 Gazette Japanese Patent Application Laid-Open No. 08-117619 International Publication No. 2002/066731 (Republished Patent WO 2002/066731) JP 2006-314252 A

  As described above, the air conditioning system for controlling the temperature of the temperature-controlled room has various forms, and a method corresponding to each purpose and temperature control target is taken. However, when air-conditioning a temperature-controlled room at a temperature of about 30 to 120 ° C., an air-conditioning system that can easily and inexpensively stably heat and cool the air-conditioning system is not always satisfactory.

  An object of the present invention is to provide an air-conditioning system that can perform heating and cooling air-conditioning easily and inexpensively based on the above-described problems.

In order to solve the above problems, the present inventors have completed the following invention.
The present invention is an air conditioning system that circulates hot water as a heat medium for adjusting the temperature of the temperature-controlled room, and includes a first heat exchanger that exchanges heat between the air in the temperature-controlled room and the hot water, An air conditioner comprising: a second heat exchanger that cools hot water discharged from the heat exchanger by heat exchange with outside air; and a heating device that heats the hot water discharged from the first heat exchanger System.

The present invention preferably includes a bypass path in the hot water introduction path to the second heat exchanger, and a switch for switching the flow path of the hot water discharged from the first heat exchanger from the second heat exchanger to the bypass path. According to a preferred aspect of the present invention, the hot water circulates in the order of the first heat exchanger, the second heat exchanger or the bypass passage, the heating device, and the first heat exchanger. The air conditioning system is characterized in that:

  In a preferred aspect of the present invention, the hot water circulates in the order of the first heat exchanger, the second heat exchanger or the heating device, and the first heat exchanger.

  Preferably, the present invention is the air conditioning system, wherein the heating device is heated by steam or hot water.

  The present invention is an air conditioning method for circulating hot water as a heat medium for adjusting the temperature of the temperature-controlled room, wherein the first heat exchanger performs heat exchange between the air in the temperature-controlled room and the hot water. The second step of cooling the warm water discharged from the first heat exchanger by heat exchange with the outside air by the second heat exchanger and the first heat exchanger by the heating device And a third step of heating hot water.

  Preferably, in the first step, when the thermostat is heated in the first step, the cooling in the second step is not performed, and when the thermostatic chamber is heated, the heating in the third step is not performed. It is the said air-conditioning method characterized.

  A preferred aspect of the present invention is the air conditioning method described above, wherein the constant temperature room has a heat source.

  In a preferred aspect of the present invention, the temperature control range of the temperature-controlled room is 120 ° C. or lower, and the outside air temperature plus 10 ° C. or higher.

  According to the present invention, it is possible to provide an air conditioning system that can easily and inexpensively stably perform heating and cooling air conditioning.

  The best mode for carrying out the present invention will be described with reference to the drawings as necessary. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of a preferred embodiment of the present invention, and does not limit the scope of the claims.

  An air conditioning system of the present invention is an air conditioning system that adjusts the temperature of a temperature-controlled room by circulating hot water as a heat medium, the air conditioning system comprising: a first heat exchanger that performs heat exchange between air and hot water; A second heat exchanger that cools the hot water discharged from the first heat exchanger by heat exchange with outside air; and a heating device that heats the hot water discharged from the first heat exchanger. Further, the hot water introduction path to the second heat exchanger is provided with a bypass path, and a switching valve for switching the flow path of the hot water discharged from the first heat exchanger from the second heat exchanger inlet to the bypass path is provided. There is an aspect provided. And in this form of the air conditioning system, the hot water bypasses the second heat exchanger by the first heat exchanger, the second heat exchanger or the bypass, and the heating device, the first heat exchanger It circulates in order and air-conditions the thermostat. The circulation pump that circulates the hot water may be disposed in the main passage other than the bypass passage. In another form of the air conditioning system, the second heat exchanger and the heating device are arranged such that hot water flows only in one of them by switching the hot water flow path. The hot water circulates in the order of the first heat exchanger via any of the first heat exchanger, the second heat exchanger, and the heating device. In this case, the circulation pump is arranged in the flow path at the outlet or inlet of the first heat exchanger. In these air conditioning systems, it is preferable that the heating device is heated by steam or hot water.

(Embodiment 1)
As Embodiment 1 of the present invention, there is an air conditioning system shown in FIG. In FIG. 1, the air conditioning system 1 takes a part of the air in the temperature-controlled room 2, cools or heats the inhaled air, returns it to the temperature-controlled room 2 by the blower 6, and controls the temperature of the temperature-controlled room 2. It has become.

  The air conditioning system 1 in this form includes a first heat exchanger 4 that exchanges heat between the air in the temperature-controlled room 2 and hot water that is a heat medium, and hot water that is discharged through heat exchange in the first heat exchanger 4. The second heat exchanger 7 that cools the water with the outside air and the heating device 10 that heats the hot water that has been heat-exchanged and discharged by the first heat exchanger 4 with steam. The first heat exchanger 4 can heat or cool the air in the temperature-controlled room 2. Hot water does not have to be pure water as long as it functions as a heat medium. In order to increase the boiling point, substances such as polyethylene glycol and inorganic compounds that have an effect of increasing the boiling point of water and freezing prevention are used. May be added. Moreover, you may add the chemical | medical agent for protection of the material which forms warm water, a flow path, and the like, such as a disinfectant, a biogeneration inhibitor, a corrosion inhibitor, and an antioxidant.

  First, the case where the temperature is adjusted by cooling the air in the temperature-controlled room 12 will be described. In the first heat exchanger 4, cold water (hot water having a relatively low temperature before being heated in the first heat exchanger is referred to as cold water) is supplied to the first heat exchanger body 5, and the suction duct The hot air in the temperature-controlled room 2 sucked from 15 is cooled. The cold water whose temperature has risen in the first heat exchanger body 5 becomes warm water and is discharged from the heat exchanger body 5, and the hot water discharge line 20 from the first heat exchanger 20, the switching valve 11, and the second heat exchange. It is introduced into the second heat exchanger 7 through a hot water supply line 21 to the vessel. In the second heat exchanger 7, the heated hot water is cooled in the second heat exchanger body 8 by the outside air introduced from the outside air intake duct 30 by the blower 9. The outside air whose temperature has increased due to the cooling of the hot water is discharged from the outside air discharge duct 31 by the blower 9. The hot water cooled by the heat exchanger body 8 becomes cold water and is discharged from the cold water discharge line 23. Then, the heat is again supplied to the first heat exchanger 4 via the heating device 10 and the circulation line 26 by the circulation pump 13 in the middle of the circulation line 24. At this time, the operation of the heating device 10 is stopped, and the valve 12 on the steam supply line 27 is closed. Thus, the cold water led to the first heat exchanger 4 by the power of the circulation pump 13 cools the high-temperature air led from the temperature-controlled room 2, and the heat absorbed by the hot water is the second heat exchanger. Is discharged together with the outside air.

  The 2nd heat exchanger 7 is a mechanism which heat-exchanges warm water with external air, and cools the heat of warm water, and cannot make warm water into temperature lower than outside air. Usually, it is desirable that the cooling is finished when the temperature of the chilled water after the heat exchange by the second heat exchanger 7 is low, up to the outside air temperature plus 5 ° C., preferably up to the outside air temperature plus 10 ° C. In order to produce cold water at a temperature lower than this, the second heat exchanger body 8 must be made very large, or the capacity of the blower 9 must be made extremely large. This is also not preferable.

  On the other hand, also in the first heat exchanger 4, the first heat that cools the air sucked from the temperature-controlled room 2 by the cold water cooled by the second heat exchanger 7 and supplied through the circulation lines 23 and 26. In view of the performance of the exchanger body 5, the temperature of the cold water supplied to the first heat exchanger body 5 plus 5 ° C. even if the temperature of the air discharged from the first heat exchanger 4 through the discharge duct 16 is low. Preferably, the temperature of the cold water plus 10 ° C. is practical.

  That is, in the temperature control of the temperature-controlled room 2, when the temperature-controlled room 2 is cooled and controlled, the temperature of the temperature-controlled room 2 is 10 from the temperature of the air that the air conditioning system 1 takes into the second heat exchanger 7 for cooling. It is desirable to control at a temperature higher than or equal to ° C, preferably higher than 20 ° C. Adjusting the temperature-controlled room 2 to a temperature lower than this by cooling often leads to an increase in equipment size, an increase in power cost, and the like. For example, if the outside air temperature is 0 ° C., the temperature of the temperature-controlled room 2 can be adjusted to 10 ° C. or higher, preferably 20 ° C. or higher. However, if the outside air temperature is 30 ° C., the temperature of the temperature-controlled room 2 is 40 ° C., preferably 50 ° C. or higher.

  Next, the case where the temperature of the temperature-controlled room 2 is adjusted by heating will be described. When heating the temperature-controlled room 2, the first heat exchanger 4 functions as an air heating device. That is, in the first heat exchanger 4, hot water is supplied to the first heat exchanger body 5, and the low-temperature air in the temperature-controlled room 2 sucked from the suction duct 15 is heated. The hot water whose temperature has dropped in the first heat exchanger body 5 is cooled and discharged from the heat exchanger body 5 and introduced into the hot water discharge line 20 and the switching valve 11 from the first heat exchanger. In the switching valve 11, the bypass line 22 side is open, the hot water supply line 21 to the second heat exchanger is closed, and cold water is introduced into the bypass line 22. The cold water is supplied from the bypass line 22 to the heating device 10 via the circulation line 24 by the circulation pump 13.

  In the heating device 10, steam is supplied by releasing the valve 12 of the steam supply line 27, and the cold water is heated to warm water. The steam exchanges heat with the heating device 10 to become condensed water, and is discharged from the drain line 29 through the steam trap 28.

  The hot water heated by the heating device 10 is supplied again to the first heat exchanger 4 via the circulation line 26. In this way, the heat obtained from the steam by the heating device 10 is guided to the first heat exchanger 4 by the power of the circulation pump 13 and heats the low-temperature air guided from the temperature-controlled room 2. Can do.

  In this air conditioning system, the temperature of the temperature-controlled room 2 can be adjusted freely, but the volume of hot water that is a heat medium changes as the adjustment temperature changes. In order to stably operate the air conditioning system corresponding to the volume change of the heat medium, the air conditioning system includes an expansion tank 14. The expansion tank 14 is preferably provided in the upper part of the entire hot water circulation system so that no air remains in the air conditioning system. The expansion tank 14 is provided with a water supply line 25 so that an appropriate amount of water level is maintained. It is also possible to pressurize the expansion tank 14 and pressurize the entire hot water circulation system to raise the boiling point of the hot water and circulate hot hot water. In this way, circulating water at 140 ° C., preferably 120 ° C. can be obtained, and the temperature of the temperature-controlled room 2 can be heated to 120 ° C., preferably 100 ° C.

  The temperature-controlled room 2 of this embodiment assumes that the preservation | save goods 3 heated to 90 degreeC are carried in continuously, for example, preserve | saved and processed for 10 hours in a constant-temperature room of 70 degreeC, and will carry out continuously after that. is doing. For this reason, the temperature-controlled room 2 includes a storage room 2a, a spare room 2b for carrying stored articles, and a spare room 3c for carrying out stored articles 3. The 90 ° C. stored article 3 carried in from the entrance 2d of the temperature-controlled room 2 is introduced into the storage chamber 2a through the spare chamber 2b. Since the storage chamber 2a is kept at 70 ° C., the storage article 3 dissipates heat and heats the air in the storage chamber 2a. For this reason, cold air of 60 ° C. is discharged from the upper part of the storage chamber 2a. The cold air is generated by the air conditioning system 1 of the present invention described above and is supplied from the temperature control air discharge duct 16. The cool air supplied from the temperature control air discharge duct 16 is distributed to the air discharge ports 18a to 18f through the distribution duct 16a and discharged. In the example shown in FIG. 1, the stored article 3 is stored for a predetermined time while moving from right to left, so the high-temperature stored article 3 that has just been carried is on the right side, and air is released more than the air outlet 18 a side. The outlet 18f side is strongly cooled. Such adjustment may be performed by the discharge air adjustment valves 19a to 19f. Here, although not illustrated, the valves 19a to 19f may be controlled in an open / closed state by an automatic control device that is linked to temperature measuring devices at various locations in the storage chamber 2a. Note that the air heated in the storage chamber 2 a is sucked into the air conditioning system 1 from the suction port 17 through the suction duct 15.

  Although the above-mentioned explanation is a case where the temperature-controlled room 2 in which the high-temperature preservation article 3 is carried continuously is cooled, the case where the temperature-controlled room 2 into which the low-temperature preservation article 3 is carried is also heated The control method of the temperature-controlled room 2 is the same except that the temperature of the introduced air and the operating state of the air conditioning system are different. Furthermore, the temperature of the temperature-controlled room 2 can be changed by heating or cooling the temperature of the temperature-controlled room 2 over time. In this case, the temperature of the temperature-controlled room 2 is compared with the programmed temperature to control whether the air-conditioning system 1 performs a cooling operation or a heating operation of the air in the temperature-controlled room 2, and the opening / closing status of the valves 19a to 19f Can be controlled. These controls may employ automatic control or may be performed artificially.

(Embodiment 2)
Another air conditioning system of the present invention will be described as a second embodiment with reference to FIG. The air conditioning system 1 of this embodiment is different from the air conditioning system described in the first embodiment in the configuration of the hot water circulation line. Specifically, in Embodiment 1, the hot water discharge line 23 from the second heat exchanger is connected to the circulation line 24, but in Embodiment 2, the hot water discharge line from the second heat exchanger. Reference numeral 23 denotes a circulation line 26 which is an outlet line of the heating apparatus 10. And in connection with this, the circulation pump 13 is arrange | positioned at the warm water discharge line 20 from a 1st heat exchanger. With such a configuration, the cold water discharged from the second heat exchanger 7 is directly circulated to the first heat exchanger 4 via the circulation line 26 without passing through the heating device 10. . In addition, since the case of the operation which heats the temperature-controlled room 2 is the same as that of Embodiment 1, description is abbreviate | omitted.

(Embodiment 3)
As another embodiment of the air conditioning system of the present invention, there is an air conditioning system in which the switching valve 11 and the bypass line 22 of the air conditioning system 1 shown in FIG. In this air conditioning system, the hot water circulation system includes a first heat exchanger 4, a hot water discharge line 20 from the first heat exchanger, a hot water supply line 21 to the second heat exchanger, and a second heat exchanger. 7. It circulates with the hot water discharge line 23, the circulation line 24, the circulation pump 13, the heating device 10, the circulation line 26, and the first heat exchanger 4 from the second heat exchanger. In this air conditioning system, in the cooling operation of the temperature-controlled room 2, the steam supply to the heating device 10 is stopped, the blower 9 of the second heat exchanger 7 is operated to cool the hot water, and the heating operation is performed. The hot water may be heated by stopping the blower 9 of the second heat exchanger 7 and supplying steam to the heating device 10.

  In addition to these embodiments, the heat source of the heating device may be an open flame such as an electric heater, hot water, or a heating furnace. Further, a plurality of circulation pumps may be provided, or other positions in the hot water circulation system, for example, on the circulation line 26 may be provided.

  The air conditioning system for controlling the temperature of the temperature-controlled room of the present application has various forms, and a form corresponding to each purpose may be adopted. In the present application, it is most effective to control the temperature-controlled room in a temperature range that is higher than the outside air temperature and lower than the hot water temperature that can be produced by the heat medium. In addition, it is possible to provide an air conditioning system that is excellent in industrial use, such as reduction in equipment costs and energy costs, ease of operation, and stability. Furthermore, the air conditioning system of the present invention uses water as a heat medium, and does not pollute the environment like chlorofluorocarbon or ammonia, or cause damage to the human body.

The constant temperature room air conditioning system of the present invention (Embodiment 1) The constant temperature room air conditioning system of the present invention (Embodiment 2) Example of constant temperature room air conditioning system using conventional air conditioner

Explanation of symbols

1: Air-conditioning system 2: Constant temperature room 2a: Storage room 2b: Preliminary room 2c: Preliminary room 2d: Inlet 2e: Outlet 3: Preserved article 4: First heat exchanger 5: First heat exchanger body 6: Blower 7: Second heat exchanger 8: Second heat exchanger body 9: Blower 10: Heating device 11: Three-way valve (switching valve)
12: Valve 13: Circulation pump 14: Expansion tank 15: Suction duct 16: Temperature control air discharge duct 16a: Distribution duct 17: Suction ports 18a to 18f: Suction ports 19a to 19f: Valve 20: From the first heat exchanger Hot water discharge line 21: Hot water supply line 22 to the second heat exchanger 22: Bypass line 23: Hot water discharge line 24 from the second heat exchanger 24: Circulation line (hot water supply line to the heating device)
25: Water supply line 26: Circulation line (hot water supply line to the first heat exchanger)
27: Steam supply line 28: Steam trap 29: Drain line 30: Outside air intake duct 31: Outside air discharge duct 101: Air conditioner 104: First heat exchanger 105: First heat exchanger tube 105a: Compressor side inlet / outlet 105b: expansion valve side inlet / outlet 106: blower 107: second heat exchanger 108: second heat exchanger tube 108a: compressor side inlet / outlet 108b: expansion valve side inlet / outlet 109: fan 110: compressor 110a: compressor inlet 110b: Compressor outlet 111: expansion valve 111a: expansion valve inlet 111b: expansion valve outlet 112: flow path switching valve 113: flow path switching valve 114: flow path switching valve 115: flow path switching valve

Claims (9)

An air conditioning system that circulates hot water as a heat medium to adjust the temperature of the temperature-controlled room,
A first heat exchanger for exchanging heat between the air in the temperature-controlled room and hot water;
A second heat exchanger that cools the hot water discharged from the first heat exchanger by heat exchange with outside air;
An air conditioning system comprising: a heating device that heats the hot water discharged from the first heat exchanger.   The hot water introduction path to the second heat exchanger includes a bypass path and a switching valve that switches the flow path of the hot water discharged from the first heat exchanger from the second heat exchanger to the bypass path. The air conditioning system according to claim 1.   The air conditioning system according to claim 2, wherein the hot water circulates in the order of the first heat exchanger, the second heat exchanger or the bypass passage, the heating device, and the first heat exchanger.   The air conditioning system according to claim 1, wherein the hot water circulates in the order of the first heat exchanger, the second heat exchanger or the heating device, and the first heat exchanger.   The air conditioning system according to any one of claims 2 to 4, wherein the heating device is heated by steam or hot water. An air conditioning method for circulating hot water as a heat medium to adjust the temperature of the temperature-controlled room,
A first step of performing heat exchange between the air in the temperature-controlled room and hot water by a first heat exchanger;
A second step of cooling the hot water discharged from the first heat exchanger by heat exchange with the outside air by the second heat exchanger;
An air conditioning method comprising: a third step of heating hot water discharged from the first heat exchanger by a heating device. In the first step, when heating the thermostat, the cooling in the second step is not performed,
The air conditioning method according to claim 6, wherein when the temperature-controlled room is heated, heating in the third step is not performed.   The air conditioning method according to claim 6 or 7, wherein a heat source is present in the temperature-controlled room.   The air conditioning method according to any one of claims 6 to 8, wherein the temperature control range of the temperature-controlled room is 120 ° C or lower and the outside air temperature plus 10 ° C or higher.

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