KR102569887B1 - Air Conditioning System And Its Control Method That Shorten The Operation Time Of The Freezer By Combining Free Cooling And Heat Storage Tank - Google Patents

Abstract

The present invention relates to an air conditioning system that shortens the operation time of a refrigerator by combining precooling and a heat storage tank and a control method thereof, and more specifically, to a cooling tower that lowers the temperature of cooling water by introducing low-temperature outdoor air at night, and heat exchange between the cooling water and the cold water By making this happen, an economizer that lowers the temperature of the chilled water, a refrigerator that forms a refrigeration cycle by the refrigerant and heat exchange between the coolant and the chilled water to lower the temperature of the chilled water, and at least one of the economizer and the refrigerator A heat storage tank for accumulating cold water whose temperature has been lowered in a water tank, and using the cold water accumulated in the heat storage tank to process the cooling load of the air conditioner during the next day, thereby minimizing the operation time of the refrigerator by summing daytime and nighttime. It relates to an air conditioning system that shortens the operating time of a refrigerator by combining free cooling and a heat storage tank and a control method thereof.
This study was conducted with the support of the Infectious Disease Medical Safety Enhancement Technology Development Project funded by the Ministry of Health and Welfare (HG22C0044).

Description

Air Conditioning System And Its Control Method That Shorten The Operation Time Of The Freezer By Combining Free Cooling And Heat Storage Tank}

The present invention relates to an air conditioning system that shortens the operation time of a refrigerator by combining free cooling and a heat storage tank, and a control method therefor, and more specifically, to a cooling load processing of an air conditioner during the day after accumulating cold water produced by a free cooling operation at night in a heat storage tank. It relates to an air conditioning system that shortens the operation time of a refrigerator by combining free cooling and a heat storage tank that can be used for air conditioning and a control method thereof.

Air conditioning refers to maintaining conditions such as temperature, humidity and air flow, bacteria, dust, and harmful gases in conditions suitable for people or items in the room. More than 50% of the total energy used in buildings is occupied by the air conditioning sector for the above-described air conditioning. In recent years, cooling operation in winter as well as summer is increasing for general office buildings due to the expansion of supply of OA devices and the management of in-house computer networks. Therefore, the air conditioning system installed in the building is continuously operated, and the total energy consumption of the building is also showing a steep increase.

Various air conditioning systems are being developed for air conditioning in conventional buildings or to increase energy efficiency. Patent Document 1 (Registered Patent Publication No. 10-2047754) relates to a multifunctional smart air conditioning system, which selectively operates a compressor according to outdoor temperature and indoor temperature conditions even when indoor ventilation and indoor air conditioning are performed at the same time. Electric energy consumption can be minimized by allowing indoor cooling and heating to be performed. However, Patent Document 1 can minimize energy consumption by controlling ON/OFF of the compressor, but the degree of energy saving is expected to be small in that it does not include an energy saving device for the refrigerator that consumes the most energy in the air conditioning system. can be expected

Patent Document 2 (Registered Patent Publication No. 10-2483126) relates to an operation control method for energy saving of an air conditioning system and an air conditioner control system using the same, an air conditioning unit including a refrigerator, a cooling water pump and a cold water pump during vapor compression, By including a control unit for controlling the operation of the air conditioning unit, it is possible to prevent the absorption chiller/heater from being operated with an excessive air ratio and to prevent carbon monoxide from being generated in the exhaust gas. However, it can be expected that the degree of energy saving will be small by adjusting the degree of energy saving by making a difference in the control method in the same device as in the prior art.

Therefore, in this technical field, there is an urgent need for a technique for adding and operating a physical device to maximize energy efficiency of an air conditioning system.

Republic of Korea Patent Registration No. 10-2047754 Republic of Korea Patent Registration No. 10-2483126

The present invention is to solve the above problems, and in order to increase the energy efficiency of a building, a combination of pre-cooling by low-temperature outdoor air and a heat storage tank capable of accumulating cold water generates and accumulates low-temperature cold water at night, and then An object of the present invention is to obtain an air conditioning system and a control method thereof that shorten the operation time of a refrigerator by combining a heat storage tank and a free cooling used for handling the cooling load of the next day.

The technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description of the present invention.

In order to achieve the above object, the air conditioning system for reducing the operation time of the refrigerator by combining the pre-cooling and the heat storage tank of the present invention includes a cooling tower that lowers the temperature of the cooling water by introducing low-temperature outdoor air at night; an economizer that lowers the temperature of the cold water by allowing heat exchange between the cooling water and the cold water; a refrigerator that forms a refrigeration cycle using a refrigerant and lowers the temperature of the cold water by allowing heat exchange between the cooling water and the cold water; and a heat storage tank for accumulating cold water whose temperature has been lowered from at least one of the economizer and the refrigerator in a water tank, and using the cold water accumulated in the heat storage tank to process the cooling load of the air conditioner during the following day, daytime and nighttime are summed. It is characterized in that the operating time of the refrigerator is minimized by doing so.

In order to achieve the above object, the control method of an air conditioning system that shortens the operation time of a refrigerator by combining the pre-cooling and the heat storage tank of the present invention lowers the temperature of the cooling water by introducing low-temperature outdoor air at night by a cooling tower, An outside air wet bulb temperature measuring step of measuring an outside air wet bulb temperature; a valve control step of controlling, by a controller, a valve to allow cold water to flow into at least one of an economizer and a refrigerator according to the outside wet bulb temperature; an accumulation step of accumulating cold water whose temperature has been lowered from at least one of the economizer and the refrigerator by means of a heat storage tank; and a cooling load processing step in which the cooling load of the air conditioner for the next day is processed by using the cold water accumulated from the accumulating step by the air conditioner, and the operation time of the refrigerator is minimized by summing daytime and nighttime. to be characterized

As described above, according to the present invention, the combination of pre-cooling by low-temperature outdoor air and a heat storage tank capable of accumulating cold water generates and accumulates low-temperature cold water at night, and then utilizes it for processing the cooling load of the air conditioner the next day during the daytime, thereby reducing building energy There is a remarkable effect of increasing building energy efficiency by not operating the chiller, which accounts for the largest amount of use, or by reducing the operating time.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the detailed description and claims.

1 is a configuration diagram of an air conditioning system that reduces operating time of a refrigerator by combining pre-cooling and a heat storage tank according to an embodiment of the present invention.
2 is a diagram showing the flow of cold water when the outside air wet bulb temperature is below a standard according to an embodiment of the present invention.
3 is a diagram showing the flow of cold water when the outside air wet bulb temperature is within a reference range according to an embodiment of the present invention.
4 is a diagram showing the flow of cold water when the outside air wet bulb temperature exceeds a standard according to an embodiment of the present invention.
5 is a flowchart of a control method of an air conditioning system that reduces operating time of a refrigerator by combining precooling and a heat storage tank according to the present invention.

The terms used in this specification have been selected from general terms that are currently widely used as much as possible while considering the functions in the present invention, but these may vary depending on the intention of a person skilled in the art, precedent, or the emergence of new technologies. In addition, in a specific case, there is also a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the invention. Therefore, the term used in the present invention should be defined based on the meaning of the term and the overall content of the present invention, not simply the name of the term.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this application, it should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. 1 is a configuration diagram of an air conditioning system that reduces operating time of a refrigerator by combining pre-cooling and a heat storage tank 400 according to an embodiment of the present invention. 2 is a diagram showing the flow of cold water when the outside air wet bulb temperature is below a standard according to an embodiment of the present invention. 3 is a diagram showing the flow of cold water when the outside air wet bulb temperature is within a reference range according to an embodiment of the present invention. 4 is a diagram showing the flow of cold water when the outside air wet bulb temperature exceeds a standard according to an embodiment of the present invention. 5 is a flowchart of a control method of an air conditioning system that reduces operating time of a refrigerator by combining pre-cooling and a heat storage tank 400 according to the present invention.

An air conditioning system that shortens the operating time of the freezer by combining pre-cooling and heat storage tank 400

Referring to FIG. 1 , an air conditioning system that reduces operating time of a refrigerator by combining precooling and a heat storage tank 400 according to the present invention may include a cooling tower 100, an economizer 200, a refrigerator 300, and a heat storage tank 400. there is. In addition, the present invention is installed in large shopping malls or public buildings to cool or heat indoor air, dehumidify or humidify, and purify the air so that people, animals, and plants living indoors can live in the most comfortable state An air handling unit (AHU) may be further included.

Indoor air can be cooled using a refrigerator connected to the conventional air conditioner 500. Since the refrigerator accounts for the majority of the total energy consumption input to the building, minimizing the use of the refrigerator is the best way to reduce the energy consumption of the building. way. Therefore, the present invention processes the cooling load of the air conditioner 500 using the cooling tower 100, the economizer 200, the refrigerator 300, and the heat storage tank 400 in order to minimize the use of the refrigerator 300, so that the refrigerator ( 300) is characterized by minimizing the operation time.

More specifically, the cooling tower 100 lowers the temperature of the cooling water by introducing low-temperature outdoor air at night.

Low-temperature outdoor air referred to in the present invention may be referred to as outside of the cooling tower 100, that is, outdoor air. In the case of a hot summer day, the temperature of the outdoor air at night may increase, and in the case of a cold winter day, the temperature of the outdoor air at night may decrease. That is, the present invention is most preferably intended to utilize low-temperature outdoor air at night by using a seasonally cold winter day or when the temperature drops after the sun goes down.

In addition, the cooling tower 100 may further include a temperature measurement unit 110 for measuring the temperature of the low-temperature outdoor air. By measuring the temperature of the incoming low-temperature outdoor air, it can be used as a criterion for controlling the plurality of valves 900 through the controller 600 in the future.

In addition, the cooling water is water circulating in a closed loop between the cooling tower 100a and the economizer 200 . The temperature of the cooling water may be lowered through heat exchange with low-temperature outdoor air in the cooling tower 100a, and this may be referred to as cooling cooling water A2. The cooling coolant A2 may flow into the economizer 200 . In addition, the cooling coolant A2 may absorb heat by exchanging heat with cold water in the economizer 200 . This may be referred to as endothermic cooling water A1. The endothermic cooling water A1 may be supplied to the cooling tower 100a through the condenser pump 700 . Further, the temperature of the endothermic cooling water A1 may be lowered again through the low-temperature outdoor air introduced from the cooling tower 100a, that is, it may become the cooling cooling water A2.

Alternatively, the cooling water is water circulating in a closed loop between the cooling towers 100b and 100c and the refrigerators 300a and 300b. The temperature of the cooling water may be lowered through heat exchange with low-temperature outdoor air in the cooling towers 100b and 100c, and this may be referred to as cooling cooling water A2. The cooling coolant A2 may flow into the freezers 300b and 300c. Further, the cooling coolant A2 may absorb heat by exchanging heat with cold water in the refrigerators 300b and 300c. This may be referred to as endothermic cooling water A1. The endothermic cooling water A1 may be supplied to the cooling towers 100b and 100c through the condenser pump 700 . Further, the temperature of the endothermic cooling water A1 may be lowered again through the low-temperature outdoor air introduced from the cooling towers 100b and 100c, that is, it may become the cooling cooling water A2.

At this time, the condenser pump 700 may condense the cooling water discharged from at least one of the economizer 200 and the refrigerator 300 and supply the water to the cooling tower 100 .

When the cooling water flows out of at least one of the economizer 200 and the refrigerator 300, the cooling water may be endothermic cooling water A1 absorbing heat from the cold water. Depending on the degree of heat absorption, it may be completely gaseous or a mixture of gaseous and liquid phases. The condenser pump 700 applies pressure to the endothermic cooling water A1 so that the liquid phase endothermic cooling water A1 can be supplied to the cooling tower 100, then exceeds the saturated vapor pressure and changes the gas phase to the liquid phase. .

Next, the economizer 200 lowers the temperature of the cold water by allowing heat exchange between the cooling water and the cold water.

The economizer 200 may also be referred to as a heat exchanger. In the economizer 200, a cooling water system through which cooling water flows and a cold water system through which cold water flows may be provided separately but adjacent to each other. In addition, when the cold water absorbed from the air conditioner 500 is supplied, the temperature of the cold water can be lowered through heat exchange with the cooling water. The cold water whose temperature is lowered may be referred to as primary heat exchange cold water B1. The primary heat exchange cold water B1 may be supplied to the refrigerator 300 through the cold water pump 800 .

At this time, the cold water pump 800 may supply the cold water discharged from the economizer 200 to at least one of the refrigerator 300 , the heat storage tank 400 and the air conditioner 500 . The cold water pump 800 may supply water to at least one of the refrigerator 300 , the heat storage tank 400 and the air conditioner 500 according to the opening/closing of the valve 900 .

Next, the refrigerator 300 lowers the temperature of the cold water by forming a refrigeration cycle using a refrigerant and allowing heat exchange between the cooling water and the cold water.

According to one embodiment of the present invention, the refrigerator 300 may include a compressor, a condenser, an evaporator, and an expansion valve. And it may include a refrigerant that circulates and a refrigerant system that is a path through which the refrigerant circulates. The refrigerator 300 may separately include a cooling water system through which cooling water flows, a cold water system through which cold water flows, and a refrigerant system through which refrigerant flows, and may form a refrigeration cycle. The cooling water referred to in the present invention may be general water at around 20 degrees, the cold water may be general water at around 7 degrees, and the refrigerant is a fluid that carries heat and may be specific chemicals such as Freon, carbon dioxide, ammonia, and methyl chloride. there is.

At this time, the refrigerant system and the cold water system may be provided adjacent to the evaporator in the refrigerator 300, and heat exchange between the refrigerant and the cold water may occur as the refrigerant absorbs heat of the cold water. That is, if the temperature of the cold water before supplying water to the evaporator was around 10 degrees, the temperature of the cold water after heat exchange with the refrigerant may be lowered to around 7 degrees. The cold water whose temperature is lowered in this way may be secondary heat exchange cold water (B2).

In addition, the condenser in the refrigerator 300 may be provided adjacent to the refrigerant system and the cooling water system, and the cooling water flowing out after being cooled from the cooling tower 100 absorbs the heat of the refrigerant, thereby preventing heat exchange between the refrigerant and the cooling water. It can happen. That is, if the refrigerant is in a high-temperature, high-pressure gas state before being supplied to the condenser, the refrigerant may be in a liquid state after heat exchange with the cooling water. In addition, if the temperature of the cooling water before being supplied to the condenser is lowered to about 28 degrees due to heat exchange with low-temperature outdoor air in the cooling tower 100, the temperature of the cooling water after heat exchange with the refrigerant may increase to about 32 degrees.

In this case, the condenser pump 700 may be further included between the condenser in the refrigerator 300 and the cooling tower 100 in the cooling water system of the refrigerator 300 . After supplying water to the condenser, the cooling water that exchanges heat with the refrigerant may have a temperature of around 32 degrees. can

However, the refrigerator 300 has a preset cooling capacity, and accordingly, it is inevitable that a plurality of refrigerators 300 are operated in a building. As mentioned above, since the refrigerator 300 accounts for most of the energy consumption of a building, it is most necessary to minimize the operation of the refrigerator 300.

Next, the heat storage tank 400 stores cold water whose temperature has been lowered from at least one of the economizer 200 and the refrigerator 300 in the water tank. Accordingly, the present invention treats the cooling load of the air conditioner 500 during the next day using the cold water accumulated in the heat storage tank 400, thereby minimizing the operation time of the refrigerator 300 by summing daytime and nighttime. to be characterized

Conventionally, when the temperature of cold water is lowered only by a refrigerator during the daytime, the refrigerator having the lowest energy efficiency operates during the daytime, which significantly increases the energy consumption of the entire air conditioning system. In order to solve this problem, the present invention provides an economizer 200, a refrigerator 300, and a heat storage tank 400 that operate through a relatively low cost of nighttime electricity by utilizing low-temperature outdoor air at night, thereby summing daytime and nighttime. Thus, there is a remarkable effect of minimizing the operating time of the refrigerator 300 having the lowest energy efficiency.

According to the present invention, at least one of the economizer 200, the refrigerator 300, and the heat storage tank 400 is measured according to the outside wet bulb temperature of the low-temperature outside air measured through the temperature measuring unit 110 in the cooling tower 100. It is characterized in that it further includes a controller 600 for controlling the valve 900 so that cold water can be introduced.

The control unit 600 includes a first valve (V1) for supplying cold water to the economizer 200 according to the outside wet bulb temperature of the low-temperature outside air, and a second valve (V1) for allowing cold water to flow bypassing the economizer 200. Valve V2, valve 3 allowing cold water discharged from the economizer 200 to flow into the heat storage tank 400, and valve 4 allowing cold water to be supplied to the refrigerator 300 ( V4) can generate a control signal that changes from a closed state to an open state. Alternatively, a control signal for changing each valve V1 to V4 from an open state to a closed state may be generated.

Referring to the embodiment of FIG. 2 , when the outside air wet bulb temperature measured by the temperature measurement unit 110 is 3 degrees Celsius or less, the controller 600 determines that the temperature of the low-temperature outside air is a temperature sufficient to lower the temperature of the cooling water. , and it can be determined that the cooling water whose temperature is sufficiently lowered is also sufficient to lower the temperature of the cold water.

Therefore, the cooling tower 100 may pre-cool the cooling water at night using cold low-temperature outdoor air. In addition, in order to produce cold water having a low temperature at night, the control unit 600 controls the number 1 valve (V1) and the number 3 valve to supply the cold water accumulated in the heat storage tank 400 to the economizer 200. (V3) can generate a control signal that changes from a closed state to an open state.

Then, the economizer 200 consumes relatively little energy and operates with nighttime electricity rather than daytime electricity, which is relatively expensive, and can produce cold water with a sufficiently low temperature. In addition, the heat storage tank 400 can recover and accumulate cold water having a sufficiently low temperature at night. Accordingly, the present invention has a remarkable effect of being able to process the cooling load of the air conditioner 500 for the next day without using the refrigerator 300 at all.

3, when the outdoor wet bulb temperature measured by the temperature measuring unit 110 is greater than 3 degrees Celsius and less than 7 degrees Celsius, the control unit 600 determines that the temperature of the low-temperature outdoor air is the cooling water It may be determined that the temperature is insufficient to lower the temperature, and the cooling water may also be determined to be insufficient to lower the temperature of the cold water.

That is, the control unit 600 includes valve 1 for supplying cold water to the economizer 200 and valve 4 for supplying cold water discharged from the economizer 200 to the refrigerator 300. A control signal for changing the valve V4 from a closed state to an open state may be generated.

Therefore, in the present invention, it is possible to pre-cool the cooling water using cool low-temperature outdoor air at night. At the same time, the present invention can produce cold water with a sufficiently low temperature by using the economizer 200 and partially the refrigerator 300, which use relatively little energy and can be operated with nighttime electricity rather than relatively expensive daytime electricity. In addition, by storing a significant amount of cold water having a sufficiently low temperature in the heat storage tank 400 at night, there is a remarkable effect of processing the cooling load of the air conditioner 500 by minimizing the operation of the refrigerator 300 during the next day.

Next, referring to the embodiment of FIG. 4 , when the outside air wet bulb temperature measured by the temperature measuring unit 110 exceeds 7 degrees Celsius, the controller 600 determines that the temperature of the low-temperature outside air is the temperature of the cooling water. It may be determined that the temperature is insufficient to lower the temperature, and the cooling water may also be determined to be insufficient to lower the temperature of the cold water.

That is, the control unit 600 can generate a control signal that changes the second valve V2 and the fourth valve V4 from the closed state to the open state so that the cold water can be directly supplied to the refrigerator 300. there is.

Therefore, in the present invention, even if precooling is not performed through the cooling tower 100, cold water having a sufficiently low temperature can be produced by using the refrigerator 300 using relatively inexpensive electricity at night. In addition, the heat storage tank 400 can accumulate cold water having a sufficiently low temperature at night. Then, the air conditioner 500 has a remarkable effect of being able to handle the cooling load of the next week while minimizing the operation of the freezer 300 during the next week.

According to the present invention, by combining pre-cooling and the heat storage tank 400, low-temperature cold water is accumulated in the heat storage tank 400 at night and then used for cooling load processing during the next day, so that the refrigerator 300 is not operated or during operation time. can be reduced and energy consumption of the refrigerator 300 can be reduced. At this time, energy consumption may increase according to the operation of the cooling tower 100, the operation of the condenser pump 700, and the operation of the cold water pump 800, but this is significantly lower than the energy consumption of the refrigerator 300, and thus the entire air conditioning system There is a remarkable effect that can realize energy saving of .

Air conditioning method for reducing operating time of a refrigerator by combining pre-cooling and heat storage tank 400

Referring to an embodiment of FIG. 5 , in the air conditioning method of reducing the operating time of the refrigerator by combining the pre-cooling and the heat storage tank 400 of the present invention, the cooling tower 100 introduces low-temperature outdoor air at night so that the temperature of the cooling water is lowered. In the outside air wet bulb temperature measurement step (S100) of measuring the outside air wet bulb temperature of the low-temperature outside air, cold water is introduced into at least one of the economizer 200 and the refrigerator 300 according to the outside air wet bulb temperature by the control unit 600. A valve control step (S200) in which the valve 900 is controlled so that the temperature of the cold water from at least one of the economizer 200 and the refrigerator 300 is accumulated by the heat storage tank 400 (S500), and A cooling load processing step (S600) of processing the cooling load of the air conditioner 500 for the next week by using the cold water accumulated from the accumulation step (S500) by the air conditioner 500 is included. Accordingly, the present invention is characterized in minimizing the operation time of the refrigerator 300 by summing daytime and nighttime.

In addition, in the control method of an air conditioning system that shortens the operation time of a refrigerator by combining the pre-cooling and the heat storage tank 400 of the present invention, heat exchange between the cooling water and the cold water is performed by the economizer 200 according to the valve state, An economizer operation step of lowering the temperature of the cold water (S300) and a refrigerator operation step (S400) of lowering the temperature of the cold water introduced according to the valve state by the refrigerator 300 through a refrigeration cycle using a refrigerant are further included. It is characterized by doing.

First, in the outdoor wet bulb temperature measuring step (S100), the cooling tower 100 introduces low-temperature outdoor air at night, thereby lowering the temperature of the cooling water and measuring the outdoor wet-bulb temperature of the low-temperature outdoor air.

Low-temperature outdoor air at night referred to in the present invention may be referred to as outside of the cooling tower 100, that is, outdoor air. In the case of a hot summer day, the temperature of the outdoor air at night may increase, and in the case of a cold winter day, the temperature of the outdoor air at night may decrease. That is, in the outdoor wet bulb temperature measuring step (S100), most preferably, low-temperature outdoor air is utilized at night by using a seasonally cold winter day or when the temperature drops after the sun goes down. In the outdoor wet bulb temperature measuring step (S100), the outdoor wet bulb temperature of the low-temperature outdoor air may be measured hourly and seasonally. Most preferably, the outside air wet bulb temperature may be within 7 degrees Celsius.

(1) Production of cold water through full-free cooling according to the outside wet bulb temperature

2, in the valve control step (S200), when the outdoor wet bulb temperature is 3 degrees Celsius or less, it may be determined that the temperature of the low-temperature outdoor air at night is a temperature sufficient to lower the temperature of the cooling water, and the temperature Cooling water with a sufficiently lowered temperature may also be determined to be sufficient to lower the temperature of the cold water.

Therefore, in the present invention, pre-cooling of the cooling water using cold low-temperature outdoor air at night is possible through the outdoor wet bulb temperature measuring step (S100).

In addition, in order to produce cold water having a low temperature at night, the valve control step (S200) includes valves 1 and 3 for supplying cold water accumulated in the heat storage tank 400 to the economizer 200. A control signal for changing the valve V3 from a closed state to an open state may be generated.

Then, in the economizer operation step (S300), the economizer 200, which consumes relatively less energy and can be operated with nighttime electricity rather than relatively expensive daytime electricity, is used, so that cold water with sufficiently low temperature can be produced. In the accumulation step (S500), cold water having a sufficiently low temperature at night may be recovered and accumulated in the heat storage tank 400 again. Therefore, the cooling load processing step (S600) has a remarkable effect that the cooling load of the air conditioner 500 for the next day can be processed without the refrigerator 300 being used at all.

Meanwhile, in the cooling load processing step (S600), if the amount of cold water accumulated in the heat storage tank 400 during the week is equal to or less than a predetermined standard, the economizer operation step (S300) and the refrigerator operation step (S400) are returned to the economizer. Cold water whose temperature is lowered by the operation 200 may be generated, and cold water whose temperature is additionally lowered by the refrigerator 300 may be generated. In addition, the cold water whose temperature has been lowered from the economizer operation step (S300) and the refrigerator operation step (S400) is not accumulated in the heat storage tank 400, but the cold water corresponding to the air conditioner 500 directly from the cooling load processing step (S600). Water can be supplied and the cooling load can be processed.

Therefore, the present invention has a remarkable effect that the operation time of the refrigerator 300, which has the lowest energy efficiency in the air conditioning system, can be minimized by summing daytime and nighttime.

(2) Production of cold water using partial-free cooling according to the outside wet bulb temperature

3, in the valve control step (S200), when the outdoor wet bulb temperature is greater than 3 degrees Celsius and less than 7 degrees Celsius, the temperature of the low-temperature outdoor air at night is not sufficient to lower the temperature of the cooling water. It may be determined that the cooling water is not sufficient to lower the temperature of the cold water.

Accordingly, in the valve control step (S200), a control signal for changing the valve V1, which allows the cold water accumulated in the heat storage tank 400 to be supplied to the economizer 200, from a closed state to an open state is generated. can be created In addition, the valve control step (S200) is a control signal in which the number 4 valve (V4) is changed from a closed state to an open state so that cold water primarily heat-exchanged from the economizer 200 can be supplied to the refrigerator 300. can be created. Then, cold water secondarily heat-exchanged from the refrigerator 300 may be recovered and accumulated in the heat storage tank 400 . At this time, the cooling water flowing into and out of the refrigerator 300 may be pre-cooled through the connected cooling tower 100b.

Therefore, in the outside air wet bulb temperature measuring step (S100) of the present invention, it is possible to pre-cool the cooling water using cool low-temperature outdoor air at night under the corresponding conditions. In addition, in the economizer operation step (S300) of the present invention, cold water having a sufficiently low temperature can be produced through the economizer 200 that consumes relatively little energy and can be operated with nighttime electricity rather than relatively expensive daytime electricity. In addition, in the refrigerator operating step (S400), the temperature of the cold water introduced from the economizer 200 may be additionally lowered. That is, both the economizer 200 and the refrigerator 300 are operated to lower the temperature of cold water.

Then, in the accumulation step (S500), cold water having a sufficiently low temperature at night may be accumulated in the heat storage tank 400. In addition, the cooling load processing step (S600) has a remarkable effect that the cooling load of the air conditioner 500 can be processed while minimizing the operation of the refrigerator 300 during the next week.

Meanwhile, in the cooling load processing step (S600), if the amount of cold water accumulated in the heat storage tank 400 during the week is equal to or less than a predetermined standard, the economizer operation step (S300) and the refrigerator operation step (S400) are returned to the economizer. Cold water whose temperature is lowered by the operation 200 may be generated, and cold water whose temperature is additionally lowered by the refrigerator 300 may be generated. In addition, the cold water whose temperature has been lowered from the economizer operation step (S300) and the refrigerator operation step (S400) is not accumulated in the heat storage tank 400, but the cold water corresponding to the air conditioner 500 directly from the cooling load processing step (S600). Water can be supplied and the cooling load can be processed.

Therefore, the present invention has a remarkable effect that the operation time of the refrigerator 300, which has the lowest energy efficiency in the air conditioning system, can be minimized by summing daytime and nighttime.

(3) Production of cold water using a chiller-cooling according to the outside wet bulb temperature

Next, referring to the embodiment of FIG. 4, in the valve control step (S200), when the outdoor wet bulb temperature exceeds 7 degrees Celsius, it is determined that the temperature of the low-temperature outdoor air is not sufficient to lower the temperature of the cooling water It may be, and it may be determined that the cooling water is not sufficient to lower the temperature of the cold water.

That is, in the valve control step (S200), a control signal for changing the second valve (V2) and the fourth valve (V4) from the closed state to the open state so that the cold water can be directly supplied to the refrigerator 300 is generated. It can be.

Therefore, in the present invention, even if pre-cooling is not performed from the outside wet bulb temperature measurement step (S100), the refrigerator 300 using relatively inexpensive nighttime electricity is used from the refrigerator operation step (S400) of the present invention to ensure that the temperature is sufficiently low. Cold water can be produced. In the accumulation step (S500), cold water having a sufficiently low temperature at night may be accumulated in the heat storage tank 400. Then, the cooling load processing step (S600) has a remarkable effect that the cooling load of the air conditioner 500 can be processed while minimizing the operation of the refrigerator 300 on the next day during the week.

Meanwhile, in the cooling load processing step (S600), if the amount of cold water accumulated in the heat storage tank 400 during the week is equal to or less than a predetermined standard, the economizer operation step (S300) and the refrigerator operation step (S400) are returned to the economizer. Cold water whose temperature is lowered by the operation 200 may be generated, and cold water whose temperature is additionally lowered by the refrigerator 300 may be generated. In addition, the cold water whose temperature has been lowered from the economizer operation step (S300) and the refrigerator operation step (S400) is not accumulated in the heat storage tank 400, but the cold water corresponding to the air conditioner 500 directly from the cooling load processing step (S600). Water can be supplied and the cooling load can be processed.

Therefore, the present invention has a remarkable effect that the operation time of the refrigerator 300, which has the lowest energy efficiency in the air conditioning system, can be minimized by summing daytime and nighttime.

Embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description language, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments that perform necessary tasks may be stored on a computer readable storage medium and executed by one or more processors.

And aspects of the subject matter described herein may be described in the general context of computer-executable instructions, such as a program module or component executed by a computer. Generally, program modules or components include routines, programs, objects, and data structures that perform particular tasks or implement particular data types. Aspects of the subject matter described herein may be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

As described above, although the embodiments have been described with limited examples and drawings, those skilled in the art can make various modifications and variations from the above description. For example, the described techniques are performed in a different order than the described method, and/or the components of the system, structure, device, circuit, etc. described in are combined or combined in a different form than the described method, or in a different configuration. Appropriate results can be achieved even when substituted or substituted by elements or equivalents.

Therefore, other implementations, other embodiments, and equivalents of the claims are within the scope of the following claims.

100.. cooling tower
110.. Temperature measuring part
200.. economizer
300.. freezer
400.. heat storage tank
500.. air conditioner
600.. control unit
700.. condenser pump
800.. cold water pump
900.. valve
A1.. Endothermic coolant
A2.. cooling coolant
B1.. 1st heat exchange cold water
B2.. 2nd heat exchange cold water
S100.. Outside wet bulb temperature measurement step
S200.. Valve control step
S300.. Economizer operation step
S400.. Refrigerator operation step
S500.. Accumulation step
S600.. Cooling load processing step

Claims (6)

A cooling tower that lowers the temperature of cooling water by introducing low-temperature outdoor air at night;
an economizer that lowers the temperature of the cold water by allowing heat exchange between the cooling water and the cold water;
a refrigerator that forms a refrigeration cycle using a refrigerant and lowers the temperature of the cold water by allowing heat exchange between the cooling water and the cold water;
a heat storage tank for accumulating cold water whose temperature has been lowered from at least one of the economizer and the refrigerator in a water tank; and
A control unit controlling a valve so that the cold water is introduced into at least one of the economizer, the refrigerator, and the heat storage tank according to the outside wet bulb temperature of the low-temperature outdoor air measured through the temperature measuring unit in the cooling tower;
The control unit,
When the outside wet bulb temperature is 3 degrees Celsius or less, it is determined that the cooling water is at a temperature sufficient to lower the temperature of the cold water, and valve 1 (V1) and the economizer allow the cold water accumulated in the heat storage tank to be supplied to the economizer. Generating a control signal that changes the valve 3 (V3) from the closed state to the open state so that the cold water flowing out from the flow can flow into the heat storage tank;
When the outdoor wet bulb temperature is greater than 3 degrees Celsius and less than 7 degrees Celsius, valve 1 determines that the cooling water is not sufficient to lower the temperature of the cold water, and allows the cold water accumulated in the heat storage tank to be supplied to the economizer (V1) and the fourth valve (V4) through which cold water discharged from the economizer is supplied to the refrigerator generates a control signal that changes from a closed state to an open state;
When the outside wet bulb temperature exceeds 7 degrees Celsius, valve 2 determines that the cooling water is not sufficient to lower the temperature of the cold water and allows the cold water accumulated in the heat storage tank to bypass the economizer and move ( V2) and the fourth valve (V4), which allows the cold water to be supplied to the refrigerator, generate a control signal that changes from a closed state to an open state,
By using the cold water accumulated in the heat storage tank at night to handle the cooling load of the air conditioner during the next day, the operation time of the freezer is minimized by summing daytime and nighttime. air conditioning system that shortens the delete According to claim 1,
A condenser pump condensing the cooling water discharged from at least one of the economizer and the refrigerator and then supplying water to the cooling tower; an air conditioning system that shortens the operation time of the refrigerator by combining the pre-cooling and the heat storage tank. According to claim 1,
A cold water pump for supplying the cold water discharged from the economizer to at least one of the refrigerator, the heat storage tank, and the air conditioner. An outside air wet bulb temperature measurement step of lowering the temperature of the cooling water by introducing low-temperature outdoor air at night by the cooling tower and measuring the outdoor wet-bulb temperature of the low-temperature outdoor air;
a valve control step of controlling, by a controller, a valve to allow cold water to flow into at least one of an economizer and a refrigerator according to the outside wet bulb temperature;
an economizer operation step of lowering the temperature of the cold water by allowing the economizer to perform heat exchange between the cooling water and the cold water according to a valve state;
a refrigerator operation step of lowering the temperature of the chilled water according to a valve state by the refrigerator through a refrigeration cycle using a refrigerant;
an accumulation step of accumulating cold water whose temperature has been lowered from at least one of the economizer and the refrigerator by means of a heat storage tank; and
A cooling load processing step in which the cooling load of the air conditioner for the next week is processed by using the cold water accumulated from the accumulation step by the air conditioner;
The valve control step,
When the outside wet bulb temperature is 3 degrees Celsius or less, it is determined that the cooling water is at a temperature sufficient to lower the temperature of the cold water, and valve 1 (V1) allowing the cold water accumulated in the heat storage tank to be supplied to the economizer and the A control signal is generated that changes the valve 3 (V3) from the closed state to the open state so that the cold water discharged from the economizer can flow into the heat storage tank;
When the outdoor wet bulb temperature is greater than 3 degrees Celsius and less than 7 degrees Celsius, it is determined that the cooling water is not sufficient to lower the temperature of the cold water, and valve 1 allows the cold water accumulated in the heat storage tank to be supplied to the economizer (V1) and the fourth valve (V4), which allows cold water flowing out of the economizer to be supplied to the refrigerator, is changed from a closed state to an open state, a control signal is generated,
When the outside wet bulb temperature exceeds 7 degrees Celsius, it is determined that the cooling water is not sufficient to lower the temperature of the cold water, and the second valve allows the cold water accumulated in the heat storage tank to bypass the economizer and move ( V2) and the fourth valve (V4), which allows the cold water to be supplied to the refrigerator, are changed from a closed state to an open state, a control signal is generated,
An air conditioning system control method for reducing the operation time of the refrigerator by combining the free cooling and the heat storage tank, characterized in that the operation time of the refrigerator is minimized by summing daytime and nighttime. delete