KR102755669B1 - High Efficiency Air-Conditioning System and Control Method thereof - Google Patents

Abstract

The present invention comprises a heat recovery heat exchanger in which a first heat medium which has passed through an evaporator in a cooling pipe and a second heat medium which has passed through a condenser in a heat-radiating pipe perform heat exchange, and by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger, the difference between a set humidity and the humidity RH1 of air entering a humidifier (set humidity - humidity RH1) is controlled to fall within a predetermined humidity range, and then by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger, the difference between a set temperature and the temperature TA1 of air entering a heating heat exchanger (set temperature - temperature TA1) is controlled to fall within a predetermined temperature range.

Description

High Efficiency Air-Conditioning System and Control Method thereof

The present invention relates to a high-efficiency air conditioning system for controlling temperature and humidity according to preset set temperature and set humidity, and a control method thereof. More specifically, the present invention relates to a high-efficiency air conditioning system for controlling temperature and humidity of air before it flows into a heating heat exchanger and a humidifier to within a predetermined temperature range and a predetermined humidity range, thereby reducing energy consumption in a heating heat exchanger and a humidifier, and a control method thereof.

The present invention is the result of the project titled “Research on basic design and basic performance data analysis of an energy-saving chamber system.”
Typically, semiconductor or display manufacturing processes are carried out in clean rooms that require high levels of cleanliness, and these clean rooms are equipped with air conditioning systems to maintain the temperature and humidity of the incoming air at preset temperature and humidity levels.

As shown in Fig. 1, a conventional air conditioning system includes an air conditioner (10) for supplying air to a clean room (1), a refrigerator (30) for cooling and dehumidifying the air above, and a heating and humidifying device (50) for heating and humidifying the air above.

An air conditioner (10) is sequentially provided with an air filter (11), a cooling heat exchanger (12), a heating heat exchanger (13), a humidifier (14), and a fan (15) in a duct (16). By the operation of the fan (15), air (SA) passing through the duct (16) is introduced into a clean room (1), and some of the air (SA) passing through the clean room (1) is discharged to the outside as exhaust (EA), and some of the air is introduced back into the clean room (1) as ventilation (RA).

Air (SA), which is a mixture of outside air (OA) and ventilation (RA) flowing in from the outside, passes through a duct (16) by the operation of a fan (15) and passes through an air filter (11), a cooling heat exchanger (12), a heating heat exchanger (13), and a humidifier (14) and then flows into a clean room (1).

In the air filter (11), foreign substances in the air (SA) flowing into the clean room (1) through the duct (16) are removed, in the cooling heat exchanger (12), the heat medium cooled by heat exchange with the refrigerant in the evaporator (31) of the refrigerator (30) passes through it and exchanges heat with the air (SA), thereby cooling and dehumidifying the air (SA), in the heating heat exchanger (13), the air (SA) is heated as the water vapor heated in the heater (51) of the heating and humidifying device (50) passes through it, and in the humidifier (14), the water vapor heated in the heater (51) of the heating and humidifying device (50) is supplied to the air (SA) to humidify it.

In the refrigerator (30), the refrigerant circulates in the order of the compressor (32), condenser (33), expansion device (34), and evaporator (31), and the high-temperature heat medium that has exchanged heat with the refrigerant in the condenser (33) is cooled in the radiator (40, cooling tower).

In addition, the heating and humidifying device (50) is equipped with a heater (51) that heats water by an electric heater or the like, and the high-temperature water vapor heated in the heater (51) heats the air (SA) through heat exchange with the air (SA) while passing through the heating heat exchanger (13) as described above, and also, a portion of the high-temperature water vapor is supplied to the air (SA) through the humidifier (14) to humidify it.

In this conventional air conditioning system, the refrigerator (30) is operated to provide the maximum cooling load regardless of the cooling load or heating load within the clean room (1), and the heating and humidifying device (50) is operated to provide the maximum heating load and humidifying amount. Therefore, the conventional air conditioning system has a problem in that the temperature and humidity of the air (SA) passing through the cooling heat exchanger (12) are significantly lower than the set temperature and set humidity of the clean room (1), and thus the energy consumption for heating and humidifying at the set temperature and set humidity in the heating and humidifying device (50) (more specifically, the heating heat exchanger (13) and the humidifier (14)) increases.

The present invention is intended to solve the problems of the conventional air conditioning system, and aims to provide a highly efficient air conditioning system and a control method thereof, which can reduce energy consumption for heating and humidifying in the heating heat exchanger and the humidifier by controlling the temperature of the heat medium flowing into the cooling heat exchanger using the condensation heat of the condenser, thereby preventing the temperature and humidity of the air entering the heating heat exchanger and the humidifier from falling significantly below the set temperature and set humidity.

In order to achieve the above object, the present invention provides an air conditioner including a cooling heat exchanger that cools and dehumidifies air, a heating heat exchanger that heats the air that has passed through the cooling heat exchanger to adjust the temperature of the air to a set temperature, and a humidifier that humidifies the air that has passed through the heating heat exchanger to adjust the humidity of the air to a set humidity, a refrigerator that includes a compressor, a condenser, an expansion device, and an evaporator, and has a refrigerant pipe that allows refrigerant to circulate in this order, a cooling pipe that allows a first heat medium cooled by heat exchange with the refrigerant while passing through the evaporator to circulate to the evaporator through the cooling heat exchanger, a heat radiation pipe that allows a second heat medium heated by heat exchange with the refrigerant while passing through the condenser to circulate to the condenser through a radiator, a heat recovery heat exchanger that heat-exchanges the first heat medium that has passed through the evaporator in the cooling pipe and the second heat medium that has passed through the condenser in the heat radiation pipe, and a heat recovery heat exchanger that branches off from the heat radiation pipe at a point (A1) of the condenser outlet in the heat radiation pipe and includes the heat recovery heat exchanger. A heat recovery pipe which passes through and joins the heat dissipation pipe at a point (A2) of the inlet of the radiator, and a control unit which changes the flow rate of the second heat medium flowing into the heat recovery heat exchanger through the heat recovery pipe, wherein the control unit changes the flow rate of the second heat medium flowing into the heat recovery heat exchanger so that the difference between the set humidity and the humidity RH1 of the air entering the humidifier (set humidity - humidity RH1) falls within a predetermined humidity range, and then changes the flow rate of the second heat medium flowing into the heat recovery heat exchanger so that the difference between the set temperature and the temperature TA1 of the air entering the heating heat exchanger (set temperature - temperature TA1) falls within a predetermined temperature range.

According to the present invention, by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger, the difference between the set humidity and the humidity RH1 of the air entering the humidifier, (set humidity - humidity RH1), is controlled to fall within a predetermined humidity range, and then, by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger, the difference between the set temperature and the temperature TA1 of the air entering the heating heat exchanger, (set temperature - temperature TA1), can be controlled to fall within a predetermined temperature range. As a result, the temperature of the air entering the heating heat exchanger can be made close to the set temperature, and also the temperature of the air entering the humidifier can be made close to the set temperature. As a result, the energy consumption for heating and humidifying in the heating heat exchanger and the humidifier can be reduced.

Figure 1 is a drawing schematically showing a conventional air conditioning system.
Figure 2 is a drawing showing an embodiment of an air conditioning system according to the present invention.
FIG. 3 is a drawing schematically showing a part of a configuration related to control in an embodiment of an air conditioning system according to the present invention.
Figure 4 is a flowchart showing a control method of an air conditioning system according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The same reference numerals are used for the same components, and redundant descriptions are omitted. In addition, for convenience of explanation, the components are depicted in a simplified manner in the drawings, and the size, ratio, etc. of each component may differ from the actual ones.

An air conditioning system according to the present embodiment comprises, as illustrated in FIG. 2, a clean room (100) in which temperature and humidity are maintained at predetermined set temperature and set humidity, and an air conditioner (200), a refrigerator (300), and a heating and humidifying device (400) for adjusting the temperature and humidity of air (SA) flowing into the clean room (100) to the set temperature and set humidity.

The air conditioner (200) has a duct (210) through which air (SA) flowing into the clean room (100) flows. In the air conditioner (200), some of the air (SA) supplied to the clean room (100) is discharged from the clean room (100) and then discharged to the outside as exhaust (EA), and some of the air can be introduced back into the duct (200) as ventilation (RA). In addition, the air conditioner (200) has a structure that allows outside air (OA) to be introduced from the outside. A mixing space (211) in which outside air (OA) and ventilation (RA) are mixed is provided in the duct (200).

In the duct (210), a mixing space (211), a cooling heat exchanger (230), a heating heat exchanger (240), a humidifier (250), and a fan (260) are arranged in this order along the direction in which air (SA) flows. The cooling heat exchanger (230) cools the air (SA) flowing in the duct (210), thereby lowering the temperature of the air (SA) and dehumidifying it.

The heating heat exchanger (240) heats the air (SA) so that the temperature of the air (SA) reaches the set temperature when the air (SA) that has passed through the cooling heat exchanger (230) has not reached the set temperature. The humidifier (250) humidifies the air (SA) so that the humidity of the air (SA) reaches the set humidity when the air (SA) that has passed through the heating heat exchanger (240) has not reached the set humidity. The fan (260) causes the air (SA) to flow through the cooling heat exchanger (230), the heating heat exchanger (240), and the humidifier (250) into the clean room (100) within the duct (210).

A temperature sensor (630) is provided between the cooling heat exchanger (230) and the heating heat exchanger (240), and the temperature TA1 of the air (SA) entering the heating heat exchanger (240) through the cooling heat exchanger (230) is measured by the temperature sensor (630). In addition, a humidity sensor (640) is provided at the inlet of the humidifier (250), and the humidity RH1 of the air (SA) entering the humidifier (250) is measured by the humidity sensor (640). The temperature TA1 of the air (SA) and the humidity RH1 of the air (SA) measured by the temperature sensor (630) and the humidity sensor (640) are sent to the control unit (900) described below and used for controlling the air conditioning system. This will be described in detail later.

The method of heat exchange between the heat medium flowing through each heat exchanger and the air (SA) in the cooling heat exchanger (230) and the heating heat exchanger (240) can adopt a method commonly used for heat exchange between two fluids, for example, a method can be adopted in which the heat medium flows through the inside of the coil-shaped cooling heat exchanger (230) and the heating exchanger (240) while the air (SA) flows through the outside to exchange heat.

The refrigerator (300) is equipped with a refrigerant pipe (L300) through which refrigerant circulates, and the refrigerant pipe (L300) includes a compressor (310) that compresses refrigerant, a condenser (320) that condenses refrigerant compressed in the compressor (310), an expansion device (330) that expands refrigerant condensed in the condenser (320), and an evaporator (340) that evaporates refrigerant expanded in the expansion device (330), which are arranged in this order.

The air conditioning system of this embodiment is equipped with a cooling pipe (L600) that allows the first heat medium to circulate through the cooling heat exchanger (230) of the air conditioner (200) and the evaporator (340) of the refrigerator (300). A circulation pump (610) that circulates the first heat medium is provided in the cooling pipe (L600). A fluid such as water or brine can be used as the first heat medium.

The first heat medium flowing through the cooling pipe ((L600) becomes low temperature after exchanging heat with the low temperature refrigerant in the evaporator (340), and thereafter, the low temperature first heat medium flows through the cooling heat exchanger (230) and cools the air (SA) through heat exchange with the air (SA), thereby lowering the temperature of the air (SA), and dehumidifying the air to lower the humidity.

In the air conditioning system of this embodiment, a heat dissipation pipe (L500) is provided for allowing the second heat medium to circulate through the condenser (320) of the refrigerator (300) and the radiator (500). A circulation pump (510) for circulating the second heat medium is provided in the heat dissipation pipe (L500). A fluid such as water or brine can be used as the second heat medium, and the same one as the first heat medium can be used. A well-known one such as a cooling tower or a dry heat exchanger can be used as the radiator (500).

The heating and humidifying device (400) in the air conditioning system of the present embodiment comprises a heater (410) that heats water, such as a boiler or a heating heater, to change water into steam or hot water, and a heating and humidifying pipe (L400) for supplying steam or hot water generated in the heater (410) to a heating heat exchanger (240) and a humidifier (250). In addition, a circulation pump (420) is provided in the heating and humidifying pipe (L400), and a heating valve (411) and a humidifying valve (412) are provided between the heater (410) and the heating heat exchanger (240) and between the heater (410) and the humidifier (250) to control the amount of steam or hot water supplied to the heating heat exchanger (240) and the humidifier (250), respectively.

In the heating heat exchanger (240), air (SA) that has passed through the cooling heat exchanger (230) is heated to a set temperature by exchanging heat with high-temperature steam or hot water passing through the heating heat exchanger (240), and in the humidifier (250), air (SA) that has passed through the heating heat exchanger (240) is humidified by mixing with steam sprayed from the humidifier (25) to reach a set humidity before entering the clean room (100).

In addition, the air conditioning system of the present embodiment is provided with a heat recovery heat exchanger (800) in which a first heat medium flowing into a cooling heat exchanger (230) through an evaporator (340) from a cooling pipe (L600) and a second heat medium flowing into a radiator (500) through a condenser (320) from a heat dissipation pipe (L500) perform heat exchange.

Specifically, the air conditioning system of the present embodiment is provided with a heat recovery pipe (L800) that branches off at a point (A1) at the outlet of a condenser (320) in a heat-radiating pipe (L500) and joins at a point (A2) at the inlet of a radiator (500). A heat recovery heat exchanger (800) is provided in the heat recovery pipe (L800). In addition, a portion of the cooling pipe (L600) between the evaporator (340) and the cooling heat exchanger (200) in the cooling pipe (L600) is provided to pass through the heat recovery heat exchanger (800).

In addition, a first valve (520) whose opening is regulated is provided between a point (A1) at the outlet of a condenser (320) where a heat recovery pipe (L800) branches off from a radiator pipe (L500) and a point (A2) at the inlet of a radiator (500) where the heat recovery pipe (L800) joins, and a second valve (810) whose opening is regulated is provided between a point (A1) in the heat recovery pipe (L800) and a heat recovery heat exchanger (800). By regulating the opening of the first valve (520) and the opening of the second valve (810), the flow rate of the second heat medium flowing into the heat recovery heat exchanger (800) through the heat recovery pipe (L800) can be regulated.

The second heat medium flowing through the heat recovery pipe ((L800)) exchanges heat with the high-temperature refrigerant in the condenser (320) and becomes high in temperature, and then flows through the heat recovery heat exchanger (800) via the second valve (810) and exchanges heat with the first heat medium flowing into the cooling heat exchanger (200) along the cooling pipe (L600) to increase the temperature of the first heat medium. The first heat medium, whose temperature has increased, increases the temperature of the air (SA) by passing through the cooling heat exchanger (200) and exchanging heat with the air (SA) passing through the cooling heat exchanger (200). As a result, the temperature of the air (SA) passing through the cooling heat exchanger (200) can be made close to the set temperature. As a result, the energy required to heat the air (SA) in the heating heat exchanger (240) to reach the set temperature can be reduced.

Meanwhile, the flow rate of the second heat medium flowing into the heat recovery heat exchanger (800) through the second valve (810) can be changed by controlling the opening of the first valve (520) and the second valve (810). In this case, the temperature of the first heat medium flowing into the heat recovery heat exchanger (800) through the cooling pipe (L600) changes, and as a result, the temperature and humidity of the air (SA) passing through the cooling heat exchanger (200) can be controlled.

As illustrated in FIG. 3, the air conditioning system of the present embodiment has a control unit (900) for controlling the air conditioning system. The control unit (900) controls the air conditioner (200), the refrigerator (300) (compressor (310), etc.), the heating and humidifying device (400) (heater, heating valve (411), humidifying valve (412), etc.), the circulation pump (510, 610), etc. by sending a control signal. In addition, the control unit (900) can receive the temperature and humidity measured by the temperature sensor (630) and the humidity sensor (640), and adjust the opening degrees of the first valve (520) and the second valve (810) based on the temperature and humidity measured by the temperature sensor (630) and the humidity sensor (640). When the opening of the first valve (520) and the second valve (810) is adjusted, the flow rate of the second heat medium flowing through the condenser (320) to the heat recovery heat exchanger (800) is adjusted, and as a result, the temperature and humidity of the air (SA) passing through the cooling heat exchanger (230) are adjusted.

The control unit (900) may be an electronic device such as a computer, tablet, mobile phone microcomputer, etc. that can exchange electrical signals with each component of the air conditioning system.

Hereinafter, a control method of the air conditioning system of the present embodiment will be described in detail with reference to FIG. 4. In FIG. 4, N is an integer that represents the number of counts used to control humidity below a certain number of times.

First, the air conditioning system is operated. Specifically, the control unit (900) operates the air conditioner (200), the refrigerator (300) (compressor (310), etc.), the heating and humidifying device (400) (heater (410), circulation pump (420), heating valve (411), humidifying valve (412), etc.), the circulation pump (510, 610), etc. (step S100).

After that, the count number N is reset to 1 (step S200), and it is checked whether N is below a certain value (step S220). Here, the certain value is 2, and if the humidity does not fall within the preset humidity range even after performing humidity control twice, the humidity is not controlled and the temperature is controlled.

First, humidity control is explained. If N is 2 or less in step S220 (Yes in step S220), the difference between the humidity RH1 measured by the humidity sensor (640) and the set humidity is controlled to fall within a preset humidity range. Here, the preset humidity range is a range in which the humidity RH1 of the air (SA) entering the humidifier (250) has a value close to the set humidity while also having a value that can be controlled by the humidifier (250). If the humidity RH1 of the air (SA) entering the humidifier (250) has a value that is too close to the set humidity, humidity control by the humidifier (250) may be difficult. Therefore, the preset humidity range has a lower limit. In addition, if the lower limit is not set, the humidity RH1 of the air (SA) entering the humidifier (250) may be greater than the set humidity, which may cause problems such as a long control time.

Assuming that the difference between the humidity RH1 of the air (SA) entering the humidifier (250) and the set humidity is within a predetermined humidity range, for example, between 5% and 10%, at step S310, (set humidity - humidity RH1) is compared with a lower limit humidity difference (for example, 5%). If at step S310, (set humidity - humidity RH1) is equal to or greater than the lower limit humidity difference (if Yes at step S310), (set humidity - humidity RH1) is compared with an upper limit humidity difference (for example, 10%) at step S320. If at step S320, (set humidity - humidity RH1) is equal to or less than the upper limit humidity difference (if Yes at step S320), the difference between the temperature TA1 measured by the temperature sensor (630) and the set temperature is adjusted to fall within a predetermined temperature range (steps subsequent to step S410).

Meanwhile, if (set humidity - humidity RH1) is less than the lower limit of the humidity difference at step S310 (if “No” at step S310), the temperature of the first heat medium passing through the cooling heat exchanger (230) is lowered to achieve more dehumidification. Specifically, first, the temperature TA1 of the air (SA) passing through the cooling heat exchanger (230) is compared with the dew point temperature (specifically, the dew point temperature corresponding to the set temperature) (step S330), and if the temperature TA1 is greater than the dew point temperature (if “Yes” at step S330), the opening degree of the second valve (810) is reduced (step S340). If the opening degree of the second valve (810) is reduced, the flow rate of the second heat medium passing through the condenser (320) and entering the heat recovery heat exchanger (800) is reduced. As a result, the temperature of the first heat medium that exchanges heat with the second heat medium in the heat recovery heat exchanger (800) decreases, and the temperature of the air (SA) that exchanges heat with the first heat medium, whose temperature has been reduced, in the cooling heat exchanger (230) decreases. This is repeated until the temperature TA1 of the air (SA) that has passed through the cooling heat exchanger (230) becomes lower than the dew point temperature corresponding to the set temperature.

In addition, if the temperature TA1 is lower than the dew point temperature at step S330 (if No at step S330), dehumidification occurs in the air (SA) passing through the cooling heat exchanger (230), thereby reducing the humidity of the air (SA). This process is repeated until (set humidity - humidity RH1) becomes higher than the lower limit of the humidity difference.

Next, in step S320, if (set humidity - humidity RH1) is greater than the upper limit of the humidity difference (if No in step S320), the opening degree of the second valve (810) is increased (step S350). When the opening degree of the second valve (810) increases, the flow rate of the second heat medium entering the heat recovery heat exchanger (800) through the condenser (320) increases. As a result, the temperature of the first heat medium that exchanges heat with the second heat medium in the heat recovery heat exchanger (800) increases, and the temperature of the air (SA) that exchanges heat with the first heat medium whose temperature has increased in the cooling heat exchanger (230) increases. As a result, the amount of dehumidification in the cooling heat exchanger (230) decreases, the humidity of the air (SA) increases, and the value of (set humidity - humidity RH1) decreases.

By repeatedly performing these steps S310 to S350, the humidity is controlled so that the humidity RH1 of the air (SA) entering the humidifier (250) falls within the preset humidity difference lower limit to humidity difference upper limit range (set humidity - humidity RH1). As a result, the humidity of the air (SA) entering the humidifier (250) through the cooling heat exchanger (230) has a value close to the set humidity. As a result, the amount of humidification applied by the humidifier (50) can be reduced to match the set humidity, thereby saving energy for humidification.

Next, in steps S410 to S472, the temperature TA1 of the air (SA) entering the heating heat exchanger (240) through the cooling heat exchanger (230) is adjusted to fall within a range of a preset lower temperature difference value to an upper temperature difference value (for example, a range of 3°C to 6°C) (set temperature - temperature TA1). Here, the preset temperature range is a range in which the temperature TA1 of the air (SA) entering the heating heat exchanger (240) is close to the set temperature while also being controllable by the heating heat exchanger (240). If the temperature TA1 of the air (SA) entering the heating heat exchanger (240) is too close to the set temperature, temperature control by the heating heat exchanger (240) may be difficult, so the preset temperature range has a lower limit. In addition, if the lower limit of the temperature range is not set, the temperature TA1 entering the heating heat exchanger (240) may be higher than the set temperature, which may cause problems such as taking a long time for control.

Specifically, first, in step S410, it is determined whether (set temperature - temperature TA1) is equal to or greater than the temperature difference lower limit. If in step S410, (set temperature - temperature TA1) is equal to or greater than the temperature difference lower limit (Yes in step S410), in step S420, it is determined whether (set temperature - temperature TA1) is equal to or less than the temperature difference upper limit.

In addition, if (set temperature - temperature TA1) is smaller than the lower temperature difference limit in step S410 (if No in step S410), the opening degree of the second valve (810) is reduced (step S430). If the opening degree of the second valve (810) is reduced, the flow rate of the second heat medium passing through the condenser (320) is reduced. As a result, the temperature of the first heat medium that exchanges heat with the second heat medium in the heat recovery heat exchanger (800) is reduced, and as a result, the temperature of the air (SA) that exchanges heat with the first heat medium whose temperature is reduced in the cooling heat exchanger (230) is reduced. By repeating this process, (set temperature - temperature TA1) becomes equal to or greater than the lower temperature difference limit.

Next, if (set temperature - temperature TA1) is greater than the temperature difference upper limit at step S420 (if “No” at step S420), it is checked whether the second valve (810) is fully opened (step S470). If the second valve (810) is fully opened at step S470 (if “Yes” at step S470), the opening degree of the first valve (520) is reduced (step S471), and if the second valve (810) is not in the opened state at step S470 (if “No” at step S470), the opening degree of the second valve (520) is increased to increase the flow rate of the second heat medium passing through the condenser (320) (step S472). In this way, when the flow rate of the second heat medium passing through the condenser (320) increases, the temperature of the first heat medium that exchanges heat with the second heat medium in the heat recovery heat exchanger (800) increases, and as a result, the temperature of the air (SA) that exchanges heat with the first heat medium whose temperature has increased in the cooling heat exchanger (230) increases. By repeating this process, (set temperature - temperature TA1) becomes equal to or lower than the upper limit of the temperature difference.

Meanwhile, if (set temperature - temperature TA1) is equal to or greater than the temperature difference lower limit at step S410 (Yes at step S410) and (set temperature - temperature TA1) is equal to or less than the temperature difference upper limit at step S420 (Yes at step S420), then it is checked at step S440 whether N is less than or equal to 2, and if less than or equal to 2, it moves to step S450, and if N exceeds 2, it is checked whether the temperature TA1 of the air (SA) entering the heating heat exchanger (240) through the cooling heat exchanger (230) is greater than the dew point temperature corresponding to the set temperature (step S460). This is to check whether dehumidification is possible in the cooling heat exchanger (230) when N exceeds 2, that is, when steps S310 to S450 are repeated twice but the humidity RH1 is not controlled within a predetermined humidity range, and steps S410, S420, S430, S470, S471, and S472 are repeated to control the temperature TA1 within a predetermined temperature range.

If the temperature TA1 of the air (SA) entering the heating heat exchanger (240) is greater than the dew point temperature corresponding to the set temperature (Yes in step S460), the opening degree of the second valve (810) is reduced (step S461), and the opening degree of the second valve (810) is reduced until the temperature TA1 becomes lower than the dew point temperature corresponding to the set temperature. When the temperature TA1 becomes lower than the dew point temperature corresponding to the set temperature, dehumidification occurs in the air (SA) passing through the cooling heat exchanger (230), thereby reducing the humidity of the air (SA) entering the humidifier (250).

In addition, if (set temperature - temperature TA1) is equal to or greater than the temperature difference lower limit at step S410 (Yes at step S410) and (set temperature - temperature TA1) is equal to or less than the temperature difference upper limit at step S420 (Yes at step S420), and if the set temperature or set humidity is not changed by the user (No at step S500), the temperature corresponding to (set temperature - temperature TA1) is heated in the heating heat exchanger (240) (step S510), and the humidity corresponding to (set humidity - humidity RH1) is humidified in the humidifier (250) (step S520). On the other hand, if the set temperature or set humidity is changed by the user (Yes at step S500), the process goes to step S200 and performs humidity control and temperature control again from the beginning.

As described above, according to the air conditioning system and the control method thereof according to the embodiment of the present invention, by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger (800), the difference between the set humidity and the humidity RH1 of the air (SA) entering the humidifier (set humidity - humidity RH1) is controlled to fall within a predetermined humidity range, and then, by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger (800), the difference between the set temperature and the temperature TA1 of the air entering the heating heat exchanger (set temperature - temperature TA1) can be controlled to fall within a predetermined temperature range. As a result, the temperature of the air (SA) entering the heating heat exchanger (240) can be made close to the set temperature, and also the temperature of the air (SA) entering the humidifier (250) can be made close to the set temperature. As a result, the energy consumption for heating and humidifying in the heating heat exchanger (240) and the humidifier (250) can be reduced.

In addition, according to the air conditioning system and the control method thereof according to the embodiment of the present invention, if the number of times in which the difference between the set humidity and the humidity RH1 of the air (SA) entering the humidifier (set humidity - humidity RH1) is not controlled to fall within a predetermined humidity range by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger (800) is greater than a certain number of times, the humidity is not controlled, and only the difference between the set temperature and the temperature TA1 of the air (SA) entering the heating heat exchanger (set temperature - temperature TA1) can be controlled to fall within the predetermined temperature range by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger (800). Accordingly, in cases in which the humidity control is not stably performed, the humidity control is not performed and only the (set temperature - temperature TA1) is controlled to fall within the predetermined temperature range, thereby preventing the humidity control from being repeated, thereby reducing energy consumption.

100 : Clean room 200 : Air conditioner
210 : Duct 230 : Cooling heat exchanger
240 : Heating heat exchanger 250 : Humidifier
300 : Refrigerator 310 : Compressor
320: Condenser 330: Expansion device
340: Evaporator 400: Heating and humidifying device
411: Heating valve 412: Humidifying valve
410 : Heater 500 : Radiator
510 : Circulation pump 520 : 1st valve
610 : Circulation pump 630 : Temperature sensor
640: Humidity sensor 800: Heat recovery heat exchanger
810: 2nd valve 900: Control unit
L300: Refrigerant piping L400: Heating and humidifying piping
L500: Heat dissipation pipe L600: Cooling pipe
L800 : Heat recovery piping

Claims (7)

An air conditioner including a cooling heat exchanger that cools and dehumidifies air, a heating heat exchanger that heats the air that has passed through the cooling heat exchanger to adjust the temperature of the air to a set temperature, and a humidifier that humidifies the air that has passed through the heating heat exchanger to adjust the humidity of the air to a set humidity.
A refrigerator comprising a compressor, a condenser, an expansion device and an evaporator, and having refrigerant piping for circulating refrigerant in this order;
A cooling pipe that allows the first heat medium, which has been cooled by heat exchange with the refrigerant while passing through the evaporator, to circulate through the cooling heat exchanger to the evaporator;
A heat dissipation pipe that allows the second heat medium, which is heated by heat exchange with the refrigerant while passing through the condenser, to circulate through the radiator to the condenser;
A heat recovery heat exchanger in which the first heat medium that has passed through the evaporator in the cooling pipe and the second heat medium that has passed through the condenser in the heat dissipation pipe exchange heat;
A heat recovery pipe branching from the heat dissipation pipe at a point (A1) of the condenser outlet in the heat dissipation pipe, passing through the heat recovery heat exchanger, and joining with the heat dissipation pipe at a point (A2) of the inlet of the heat dissipation pipe,
A control unit is provided for changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger through the heat recovery pipe.
An air conditioning system characterized in that the control unit changes the flow rate of the second heat medium flowing into the heat recovery heat exchanger to adjust the difference between the set humidity and the humidity RH1 of the air entering the humidifier (set humidity - humidity RH1) to fall within a predetermined humidity range, and then changes the flow rate of the second heat medium flowing into the heat recovery heat exchanger to adjust the difference between the set temperature and the temperature TA1 of the air entering the heating heat exchanger (set temperature - temperature TA1) to fall within a predetermined temperature range. In claim 1,
An air conditioning system characterized in that, when the number of times that the control unit does not adjust the difference between the set humidity and the humidity RH1 of the air entering the humidifier (set humidity - humidity RH1) by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger to fall within a predetermined humidity range exceeds a certain number of times, the control unit does not perform humidity control and instead adjusts the flow rate of the second heat medium flowing into the heat recovery heat exchanger so that only the difference between the set temperature and the temperature TA1 of the air entering the heating heat exchanger (set temperature - temperature TA1) falls within a predetermined temperature range. In claim 2,
An air conditioning system characterized in that the control unit changes the flow rate of the second heat medium flowing into the heat recovery heat exchanger so that only the difference (set temperature - temperature TA1) between the set temperature and the temperature TA1 of air entering the heating heat exchanger falls within a predetermined temperature range by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger so that the temperature TA1 of the air entering the heating heat exchanger becomes lower than the dew point temperature corresponding to the set temperature. In any one of claims 1 to 3,
A first valve is provided between the condenser outlet of the heat dissipation pipe and the radiator and capable of controlling the opening, and a second valve is provided between a point (A1) of the heat dissipation pipe and the heat recovery heat exchanger in the heat recovery pipe and capable of controlling the opening.
An air conditioning system characterized in that the control unit, when controlling the difference between the set temperature and the temperature TA1 of air entering the heating heat exchanger (set temperature - temperature TA1), falls within a predetermined temperature range, controls the opening of the first valve when the second valve is in the expanded state to change the flow rate of the second heat medium flowing into the heat recovery heat exchanger. A method for controlling an air conditioning system as described in claim 1,
A humidity control step for controlling humidity so that the difference between the set humidity and the humidity RH1 of the air entering the humidifier (set humidity - humidity RH1) falls within a predetermined humidity range by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger,
A control method for an air conditioning system, characterized in that it includes a temperature control step for controlling the temperature so that the difference between the set temperature and the temperature TA1 of air entering the heating heat exchanger (set temperature - temperature TA1) falls within a predetermined temperature range by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger after the humidity control step. In claim 5,
A control method for an air conditioning system, characterized in that, in the humidity control step, if the number of times that the difference (set humidity - humidity RH1), which is the difference between the set humidity and the humidity RH1 of the air entering the humidifier, is not controlled to fall within a predetermined humidity range is greater than or equal to a predetermined number of times, the temperature is controlled so that only the difference (set temperature - temperature TA1), which is the difference between the set temperature and the temperature TA1 of the air entering the heating heat exchanger, falls within a predetermined temperature range by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger. In claim 5 or claim 6,
A control method of an air conditioning system, characterized in that by changing the flow rate of the second heat medium flowing into the heat recovery heat exchanger, only the difference (set temperature - temperature TA1) between the set temperature and the temperature TA1 of air entering the heating heat exchanger is controlled to fall within a predetermined temperature range, and then the flow rate of the second heat medium flowing into the heat recovery heat exchanger is changed so that the temperature TA1 of the air entering the heating heat exchanger becomes lower than the dew point temperature corresponding to the set temperature.

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