Air conditioning system and control method thereof

Abstract

The invention relates to an air conditioning system and a control method thereof. The air conditioning system comprises a clean workshop; the output end of the fresh air handling unit is connected with the clean workshop, and the fresh air handling unit is used for conveying outdoor fresh air; the return air adjusting assembly comprises a cooling tower and a three-medium heat exchanger, the cooling tower is provided with a first input end, the input end of the cooling tower is connected with the first output end of the three-medium heat exchanger, the output end of the cooling tower is connected with the first input end of the three-medium heat exchanger, and the three-medium heat exchanger is connected with the output end of the fresh air handling unit; the temperature of the supplied air entering the clean workshop is adjusted; if the air conditioning system operates in the transition season, cooling water of the cooling tower is controlled to enter the three-medium heat exchanger and exchanges heat with return air of the clean workshop, so that the cooled air enters the clean workshop after being mixed with outdoor fresh air, the low-temperature cooling water of the cooling tower can be used for cooling the return air, and therefore the overall power consumption of the system is reduced; and the energy-saving performance of the system is improved.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioning, and in particular to an air conditioning system and a control method thereof. Background Art

[0002] Cleanroom construction is huge in scale. The energy consumption of cleanrooms is 10 to 30 times that of general office buildings, and the energy consumption of purification air conditioning systems is 5 to 15 times that of general air conditioning systems. Semiconductor cleanroom air conditioning has the characteristics of high load, multiple parameters, and long operation time, which has high requirements for HVAC design. The construction investment of high-level semiconductor factories is very expensive, and the energy consumption is huge. Therefore, energy saving and reducing the cost of semiconductor factory HVAC systems are urgent needs in HVAC design.

[0003] At present, the air in high-grade clean workshops is sent into the clean workshop from the clean ceiling interlayer by FFU (Fan Filter Unit), and the circulating air is sent back to the ceiling interlayer through the return air channel. When the circulating air passes through the return air channel, it exchanges heat with the DCC dry coil installed in the channel. The cold source of the dry coil in traditional projects is the medium-temperature water output by the medium-temperature refrigeration host. When the air-conditioning system of the existing clean workshop is running in the transition season, the temperature of the outdoor fresh air itself is not too high, and the cooling return water temperature of the medium-temperature chiller is low. The cooling return water temperature of the medium-temperature chiller enters the dry coil to reduce the return air temperature. After the return air and fresh air are mixed, the clean workshop is cooled, resulting in high system energy consumption, which is not conducive to energy saving. Summary of the invention

[0004] The present application provides an air conditioning system and a control method thereof to solve the technical problems of low system stability and high energy consumption of a medium-temperature main engine when the air conditioning system of an existing clean workshop is operated in a transition season.

[0005] In a first aspect, the present application provides an air conditioning system, comprising: a clean workshop;

[0006] The fresh air unit, whose output end is connected to the clean room, is used to transport outdoor fresh air; and

[0007] The return air conditioning component includes a cooling tower and a three-medium heat exchanger, wherein the cooling tower has a first input end, the input end of the cooling tower is connected to the first output end of the three-medium heat exchanger, the output end of the cooling tower is connected to the first input end of the three-medium heat exchanger, and the three-medium heat exchanger is connected to the output end of the fresh air unit to adjust the supply air temperature entering the clean room;

[0008] Among them, if the air-conditioning system is operated in the transition season, the cooling water of the cooling tower is controlled to enter the three-medium heat exchanger and exchange heat with the return air of the clean room, so that the cooled air is mixed with the outdoor fresh air and enters the clean room.

[0009] In one possible implementation, the return air conditioning assembly includes a first pipeline and a first control valve, the first end of the first pipeline is connected to the output end of the cooling tower, the second end of the first pipeline is connected to the first input end of the three-medium heat exchanger, and the first control valve is arranged on the first pipeline.

[0010] In a possible implementation, the return air conditioning component includes:

[0011] The medium-temperature chiller comprises a condenser and an evaporator, wherein the condenser is connected to a cooling tower, the input end of the evaporator is connected to the second output end of the three-medium heat exchanger, and the output end of the evaporator is connected to the second input end of the three-medium heat exchanger;

[0012] A second pipeline, a first end of which is connected to an output end of the cooling tower, and a second end of which is connected to an input end of the condenser; and

[0013] A second control valve is arranged on the second pipeline;

[0014] The air conditioning system also includes a first temperature sensor for detecting the outlet air temperature of the three-medium heat exchanger;

[0015] If the outlet air temperature of the three-medium heat exchanger is greater than the target return air temperature, the opening of the first control valve is controlled to decrease, and the opening of the second control valve is controlled to increase.

[0016] In one possible implementation, the return air conditioning assembly includes a third pipeline, a first end of the third pipeline is connected to the output end of the cooling tower, a second end of the third pipeline is simultaneously connected to the first end of the first pipeline and the first end of the second pipeline, and a first water pump is arranged on the third pipeline.

[0017] In a possible implementation, the return air conditioning assembly includes a fourth pipeline, a first end of the fourth pipeline is connected to the output end of the evaporator, a second end of the fourth pipeline is connected to the second input end of the three-medium heat exchanger, and a second water pump is arranged on the fourth pipeline.

[0018] In a possible implementation, it includes an air supply channel and a return air channel, a first end of the air supply channel is connected to the output end of the fresh air unit, and a second end of the air supply channel is connected to the clean room;

[0019] The first end of the return air channel is connected to the clean room, and the second end of the return air channel is connected to the first end of the supply air channel;

[0020] The three-medium heat exchanger is arranged on the return air channel so that the air in the clean room can exchange heat with the medium flowing inside the three-medium heat exchanger.

[0021] In a possible implementation, the air supply channel has an air supply section, and the air supply section of the air supply channel is provided with a filter unit assembly.

[0022] In a possible implementation, the air supply channel has an air mixing section, the air mixing section of the air supply channel is arranged at a first end of the air supply channel, and the air mixing section of the air supply channel is provided with a first temperature and humidity sensor.

[0023] In a possible implementation, a fresh air channel is provided at the output end of the fresh air unit, one end of the fresh air channel away from the fresh air unit is connected to the mixed air section of the air supply channel, and a second temperature and humidity sensor is provided on the fresh air channel.

[0024] In a possible implementation, a second temperature detection device is included, and the second temperature detection device is used to detect the outlet water temperature of the cooling tower;

[0025] If the outlet water temperature of the cooling tower is lower than the minimum target inlet water temperature, the first control valve is controlled to open and the second control valve is controlled to close.

[0026] On the second aspect, the present application also provides a control method for an air-conditioning system, which is applied to the previous air-conditioning system, and the control method includes: obtaining the operating conditions of the air-conditioning system; if the air-conditioning system is operating in the transition season, controlling the cooling water of the cooling tower to enter the three-medium heat exchanger for heat exchange, so that the cooled air is mixed with the outdoor fresh air and enters the clean workshop.

[0027] In a possible implementation, the air conditioning system includes a first pipeline, a first control valve, a condenser, a second pipeline, a second control valve, an evaporator, and a first temperature sensor, and the control method includes:

[0028] If the outlet air temperature of the three-medium heat exchanger is greater than the target return air temperature, the opening of the first control valve is controlled to decrease, and the opening of the second control valve is controlled to increase until the outlet air temperature of the three-medium heat exchanger is less than or equal to the target return air temperature.

[0029] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0030] The embodiment of the present application provides an air conditioning system and a control method thereof. When operating in the transition season, the outdoor temperature conditions are good, that is, the temperature of the outdoor fresh air is relatively low in summer. The low-temperature cooling water flowing out of the cooling tower is transported to the three-medium heat exchanger. The low-temperature cooling water in the three-medium heat exchanger exchanges heat with the air through heat conduction and heat convection, so that the return air of the clean room is cooled. The cooled return air is mixed with the outdoor fresh air transported by the fresh air unit and enters the clean room. The heated cooling water enters the cooling tower to dissipate heat and cool down. The cooled cooling water is transported to the three-medium heat exchanger to realize the circulation of cooling water. This circulation process only uses the cooling water of the cooling tower to adjust the return air temperature, and then adjusts the supply air temperature entering the clean room. Compared with the prior art, when operating in the transition season, the present application uses the low-temperature cooling water of the cooling tower to cool the return air, and the medium-temperature chiller can be shut down, thereby reducing the overall power consumption of the system and improving the energy saving of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0033] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0034] Figure 1 A schematic diagram of the structure of an air conditioning system provided in one embodiment of the present application;

[0035] Figure 2 for Figure 1 A schematic diagram showing the working principle of an air conditioning system Figure 1 , wherein the solid arrow direction shows the water flow direction;

[0036] Figure 3 for Figure 1 A schematic diagram showing the working principle of an air conditioning system Figure 2 , wherein the solid arrow direction shows the water flow direction;

[0037] Figure 4 for Figure 1 A schematic diagram showing the working principle of an air conditioning system Figure 3, wherein the solid arrow direction shows the water flow direction;

[0038] Figure 5 A schematic diagram of the structure of an air conditioning system provided in another embodiment of the present application;

[0039] Figure 6 A flow chart of a method for controlling an air-conditioning system provided in an embodiment of the present application.

[0040] Description of reference numerals:

[0041] 1. Clean room; 2. Fresh air unit; 21. Fresh air channel; 211. Second temperature and humidity sensor; 3. Return air conditioning assembly; 31. Cooling tower; 32. Three-medium heat exchanger; 33. Medium-temperature chiller; 331. Condenser; 332. Evaporator; 4. Air supply channel; 41. Air supply section; 42. Mixed air section; 421. First temperature and humidity sensor; 5. Return air channel; 51. First temperature sensor; 6. Filter unit;

[0042] G1, first pipeline; G2, second pipeline; G3, third pipeline; G31, first water pump; G32, second temperature detection device; G4, fourth pipeline; G41, second water pump;

[0043] V1, first control valve; V2, second control valve. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0045] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0046] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", "front", "back", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure undergoes a position flip or a posture change or a motion state change, these directional indications will also change accordingly, for example: an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

[0047] In order to solve the technical problems in the prior art that the air-conditioning system of a clean workshop has low system stability and high energy consumption of the medium-temperature main unit when operating in the transition season, the present application provides an air-conditioning system and a control method thereof, which can utilize the low-temperature cooling water of the cooling tower to cool the return air, and the medium-temperature chiller can be shut down, thereby reducing the overall power consumption of the system and improving the energy efficiency of the system.

[0048] Figure 1 An air conditioning system provided for an embodiment of the present application includes a clean workshop 1, a fresh air unit 2, and a return air conditioning component 3, wherein the input end of the fresh air unit 2 is connected to the outdoors, and the output end of the fresh air unit 2 is connected to the clean workshop 1 for conveying outdoor fresh air; the return air conditioning component 3 includes a cooling tower 31 and a three-medium heat exchanger 32, the cooling tower 31 has a first input end, the input end of the cooling tower 31 is connected to the first output end of the three-medium heat exchanger 32, the output end of the cooling tower 31 is connected to the first input end of the three-medium heat exchanger 32, and the three-medium heat exchanger 32 is connected to the output end of the fresh air unit 2 to adjust the supply air temperature entering the clean workshop 1; wherein, if the air conditioning system is operated in the transition season, the cooling water of the cooling tower 31 is controlled to enter the three-medium heat exchanger 32 and exchange heat with the return air of the clean workshop 1, so that the cooled return air is mixed with the outdoor fresh air and enters the clean workshop 1.

[0049] It is understandable that if Figure 2As shown, when operating in the transition season, the outdoor temperature conditions are good, that is, the temperature of the outdoor fresh air is relatively low in summer, and the low-temperature cooling water flowing out of the cooling tower 31 is transported to the three-medium heat exchanger 32. The low-temperature cooling water in the three-medium heat exchanger 32 exchanges heat with the air through heat conduction and heat convection, so that the return air of the clean workshop 1 is cooled. The cooled return air is mixed with the outdoor fresh air transported by the fresh air unit 2 and enters the clean workshop 1. The heated cooling water enters the cooling tower 31 to dissipate heat and cool down. The cooled cooling water is transported to the three-medium heat exchanger 32 to realize the circulation of cooling water. This circulation process only uses the cooling water of the cooling tower 31 to adjust the return air temperature, and then adjusts the supply air temperature entering the clean workshop 1. Compared with the prior art, when operating in the transition season, the present application uses the low-temperature cooling water of the cooling tower 31 to cool the return air, and the medium-temperature chiller 33 can be shut down, thereby reducing the overall power consumption of the system and improving the energy saving of the system.

[0050] It should be noted that the three-medium heat exchanger 32 may include a dry coil (Dry Cooling Coil, DCC, dry cooling coil, referred to as dry coil), which controls the indoor temperature by eliminating the sensible heat of the clean workshop 1 (such as the heat generated by people, lighting, machinery and equipment, etc.), and generally does not produce condensed water.

[0051] Furthermore, the return air conditioning assembly 3 includes a first pipeline G1 and a first control valve V1, the first end of the first pipeline G1 is connected to the output end of the cooling tower 31, the second end of the first pipeline G1 is connected to the first input end of the three-medium heat exchanger 32, and the first control valve V1 is arranged on the first pipeline G1.

[0052] When the transition season is running, Figure 2 As shown, the first control valve V1 is fully opened, and the low-temperature cooling water flowing out of the cooling tower 31 is transported to the three-medium heat exchanger 32 through the first pipeline G1. The low-temperature cooling water in the three-medium heat exchanger 32 exchanges heat with the air through heat conduction and heat convection, so that the return air of the clean workshop 1 is cooled. The cooled return air is mixed with the outdoor fresh air transported by the fresh air unit 2 and then enters the clean workshop 1.

[0053] In some embodiments, the return air conditioning assembly 3 includes a medium-temperature chiller 33, a second pipeline G2 and a second control valve V2. The medium-temperature chiller 33 includes a condenser 331 and an evaporator 332. The condenser 331 is connected to the cooling tower 31. Specifically, the input end of the condenser 331 is connected to the output end of the cooling tower 31, and the output end of the condenser 331 is connected to the input end of the cooling tower 31 to form a cooling water cycle; the input end of the evaporator 332 is connected to the second output end of the three-medium heat exchanger 32, and the output end of the evaporator 332 is connected to the input end of the cooling tower 31. The output end is connected to the second input end of the three-medium heat exchanger 32; the first end of the second pipeline G2 is connected to the output end of the cooling tower 31, and the second end of the second pipeline G2 is connected to the input end of the condenser 331; the second control valve V2 is arranged on the second pipeline G2; the air conditioning system includes a first temperature sensor 51, which is used to detect the outlet air temperature T1 of the three-medium heat exchanger 32; wherein, if the outlet air temperature of the three-medium heat exchanger 32 is greater than the target return air temperature Tm1, the opening of the first control valve V1 is controlled to decrease, and the second control valve V2 is opened.

[0054] If T1>Tm1, Figure 3 As shown, it means that the return air temperature is too high, that is, the cooling capacity of the clean workshop 1 cannot meet the demand, so the second control valve V2 is opened, the medium-temperature chiller 33 is started, and a part of the cooling water flowing out of the cooling tower 31 is transported to the three-medium heat exchanger 32 through the first pipeline G1, and absorbs heat and heats up through the dry coil of the three-medium heat exchanger 32, and reduces the return air temperature; another part of the cooling water is transported to the condenser 331 of the medium-temperature chiller 33 through the second pipeline G2, and absorbs heat and heats up through the condenser 331. The heated cooling water is all dissipated and cooled through the cooling tower 31, and then transported to the three-medium heat exchanger 32 and the condenser 331 to form a cycle. At the same time, the low-temperature refrigerant (medium-temperature water) flowing out of the evaporator 332 flows into the three-medium heat exchanger 32, and the low-temperature refrigerant absorbs heat and heats up through the dry coil of the three-medium heat exchanger 32, and reduces the return air temperature. In this process, the cooling water of the cooling tower 31 and the medium-temperature water flowing out of the evaporator 332 are used to jointly adjust the return air temperature until T1≤Tm1, so that the outlet air temperature of the three-medium heat exchanger 32 meets the target return air temperature, and then the return air and the fresh air meet the cooling demand of the clean workshop 1 after the return.

[0055] After the first time t1, if T1>Tm1, the opening of the first control valve V1 can be controlled to decrease, and the opening of the second control valve V2 can be increased. The return air temperature can be adjusted by reducing the cooling water flow through the dry coil of the three-medium heat exchanger 32 and increasing the medium-temperature water flow until T1≤Tm1.

[0056] After the second time t2, t1<t2, if T1>Tm1, the first control valve V1 can be closed and the second control valve V2 can be fully opened. At this time, the three-medium heat exchanger 32 only uses medium-temperature water to adjust the return air temperature.

[0057] Of course, if the air conditioning system is operated in summer, Figure 4 As shown, the first control valve V1 can be closed and the second control valve V2 can be fully opened. The cooling water is transported to the condenser 331 of the medium-temperature chiller 33, and the condenser 331 absorbs heat and heats up. The heated cooling water is all cooled by the cooling tower 31 to form a cycle. At this time, the three-medium heat exchanger 32 only uses the medium-temperature water of the evaporator 332 to adjust the return air temperature, thereby realizing the refrigeration of the clean workshop 1.

[0058] Furthermore, the air conditioning system includes a third pipeline G3, a first end of the third pipeline G3 is connected to the output end of the cooling tower 31, a second end of the third pipeline G3 is simultaneously connected to the first end of the first pipeline G1 and the first end of the second pipeline G2, and a first water pump G31 is provided on the third pipeline G3.

[0059] When the air-conditioning system is operated in summer, the cooling water flowing out of the output end of the cooling tower 31 is transported to the condenser 331 of the medium-temperature chiller 33 through the first water pump G31, and absorbs heat and heats up through the condenser 331. The heated cooling water all passes through the cooling tower 31 to dissipate heat and cool down, forming a cycle. At this time, the three-medium heat exchanger 32 only uses the medium-temperature water of the evaporator 332 to adjust the return air temperature, thereby realizing the refrigeration of the clean workshop 1; when the air-conditioning system is operated in the transition season, the cooling water flowing out of the output end of the cooling tower 31 determines the return air cooling demand according to the outlet air temperature of the three-medium heat exchanger 32, and the cooling water can be transported to the condenser 331 of the medium-temperature chiller 33 through the first water pump G31, or the cooling water can be directly transported to the three-medium heat exchanger 32, or part of the cooling water can be transported to the condenser 331 and part of the cooling water can be transported to the three-medium heat exchanger 32.

[0060] Furthermore, the return air conditioning assembly 3 includes a fourth pipeline G4, a first end of the fourth pipeline G4 is connected to the output end of the evaporator 332, a second end of the fourth pipeline G4 is connected to the second input end of the three-medium heat exchanger 32, and a second water pump G41 is provided on the fourth pipeline G4.

[0061] When operating in summer or in transitional seasons, the medium-temperature water of the evaporator 332 can be delivered by the second water pump G41 to adjust the return air temperature and ensure the cooling demand of the clean workshop 1.

[0062] In some embodiments, the air conditioning system includes an air supply duct 4 and a return air duct 5. The first end of the air supply duct 4 is connected to the output end of the fresh air unit 2, and the second end of the air supply duct 4 is connected to the clean workshop 1; the first end of the return air duct 5 is connected to the clean workshop 1, and the second end of the return air duct 5 is connected to the first end of the air supply duct 4; the three-medium heat exchanger 32 is arranged on the return air duct 5 to enable the air in the clean workshop 1 to exchange heat with the medium flowing inside the three-medium heat exchanger 32.

[0063] The fresh air unit 2 transports outdoor fresh air to the air supply duct 4. The air in the clean workshop 1 exchanges heat with the medium circulating inside the three-medium heat exchanger 32 in the return air duct 5. The cooled return air enters the air supply duct 4 through the return air duct 5 and mixes with the outdoor fresh air, and finally enters the clean workshop 1 to realize air circulation.

[0064] Optionally, the first temperature sensor 51 may be disposed on the return air channel 5 , and the first temperature sensor 51 is located at the air outlet end of the three-medium heat exchanger 32 .

[0065] Furthermore, the air supply channel 4 has an air supply section 41 , and the air supply section 41 of the air supply channel 4 is provided with a filter unit assembly 6 .

[0066] The filter unit unit 6 can adopt the existing fan filter unit unit (FFU), which is a purification air conditioning terminal composed of a high-efficiency filter (HEPA) or an ultra-high-efficiency filter (ULPA), a micro fan, and a shell. The cooled return air is mixed with the outdoor fresh air and then sent into the clean workshop 1 through the filter unit unit 6, which can deliver high-quality air to the clean workshop 1.

[0067] Furthermore, the air supply channel 4 has an air mixing section 42 , the air mixing section 42 of the air supply channel 4 is arranged at a first end of the air supply channel 4 , and the air mixing section 42 of the air supply channel 4 is provided with a first temperature and humidity sensor 421 .

[0068] The air mixing section 42 should be long enough to ensure that the temperature of the mixed air sent to the clean room 1 is uniform enough, thereby ensuring the temperature uniformity of the clean room 1. The first temperature and humidity sensor 421 can detect the mixed air temperature T3 and the corresponding wet bulb temperature Ts1 of the mixed air to determine the target return air temperature Tm1.

[0069] Alternatively, if Figure 5 As shown, a fresh air channel 21 is provided at the output end of the fresh air unit 2, and one end of the fresh air channel 21 away from the fresh air unit 2 is connected to the air mixing section 42 of the air supply channel 4, and a second temperature and humidity sensor 211 is provided on the fresh air channel 21.

[0070] The outdoor fresh air enters the mixed air section 42 of the air supply channel 4 through the fresh air channel 21, so that the outdoor fresh air is mixed with the cooled return air, and the mixed air enters the clean room 1 through the air supply section 41 of the air supply channel 4. The second temperature and humidity sensor 211 can detect the temperature T4 of the outdoor fresh air and the corresponding wet bulb temperature Ts2. T4, Ts2 and the above T3 and Ts1 jointly determine the target return air temperature Tm1.

[0071] In some embodiments, the air-conditioning system also includes a second temperature detection device G32, which is used to detect the outlet water temperature T2 of the cooling tower 31. The second temperature detection device G32 can be arranged on the third pipeline G3; if the air-conditioning system is operated in the transition season and the outlet water temperature of the cooling tower 31 is lower than the minimum target inlet water temperature Tm2, ​​the first control valve V1 is controlled to be opened and the second control valve V2 is controlled to be closed.

[0072] Specifically, the temperature of the cooling water after cooling by the cooling tower 31 is detected by the second temperature detection device G32. The inlet water temperature range of the cooling tower 31 for stable operation of the air-conditioning system is Tm2≤T2≤Tm3. If the air-conditioning system is operated in the transition season and T2<Tm2, it means that the outdoor temperature conditions are good enough. At this time, the first control valve V1 is controlled to be opened and the second control valve V2 is closed. The low-temperature cooling water flowing out of the cooling tower 31 is transported to the three-medium heat exchanger 32. The low-temperature cooling water in the three-medium heat exchanger 32 exchanges heat with the air through heat conduction and heat convection, so that the return air of the clean workshop 1 is cooled. The cooled return air is mixed with the outdoor fresh air transported by the fresh air unit 2 and enters the clean workshop 1. The heated cooling water enters the cooling tower 31 for heat dissipation and cooling. The cooled cooling water is then transported to the three-medium heat exchanger 32 to realize the circulation of cooling water. In this circulation process, only the cooling water of the cooling tower 31 is used to adjust the return air temperature, and then the supply air temperature entering the clean workshop 1 is adjusted, thereby reducing the energy consumption of the air-conditioning system and improving the operation stability of the system.

[0073] It should be noted that as long as any one of the two temperature conditions of T1>Tm1 and T2<Tm2 is met, the three-medium heat exchanger 32 can use the cooling water of the cooling tower 31 to adjust the return air temperature to reduce the energy consumption of the system.

[0074] Figure 6 A control method for an air conditioning system provided in an embodiment of the present application is applied to the air conditioning system as described above, and the control method comprises the following steps:

[0075] S1. Obtaining the working condition of the air conditioning system;

[0076] S2. If the air conditioning system is operated in the transition season, the cooling water of the cooling tower 31 is controlled to enter the three-medium heat exchanger 32 for heat exchange, so that the cooled air is mixed with the outdoor fresh air and then enters the clean workshop 1.

[0077] During operation in the transition season, the outdoor temperature conditions are good, and the low-temperature cooling water flowing out of the cooling tower 31 is transported to the three-medium heat exchanger 32. The low-temperature cooling water in the three-medium heat exchanger 32 exchanges heat with the air through heat conduction and heat convection, so that the return air of the clean workshop 1 is cooled. The cooled return air is mixed with the outdoor fresh air transported by the fresh air unit 2 and enters the clean workshop 1. The heated cooling water enters the cooling tower 31 for heat dissipation and cooling. The cooled cooling water is then transported to the three-medium heat exchanger 32 to realize the circulation of cooling water. In this circulation process, only the cooling water of the cooling tower 31 is used to adjust the return air temperature, and then the supply air temperature entering the clean workshop 1 is adjusted. The low-temperature cooling water of the cooling tower 31 is used to cool the return air, and the medium-temperature chiller 33 can be shut down, thereby reducing the overall power consumption of the system and improving the energy saving of the system.

[0078] In some embodiments, the air conditioning system includes a first pipeline G1, a first control valve V1, a medium-temperature chiller 33, a second pipeline G2, a second control valve V2 and a first temperature sensor 51, and the control method includes: if the outlet air temperature of the three-medium heat exchanger 32 is greater than the target return air temperature, then the opening of the first control valve V1 is controlled to decrease, and the opening of the second control valve V2 is increased until the outlet air temperature of the three-medium heat exchanger 32 is less than or equal to the target return air temperature.

[0079] If T1>Tm1, it means that the return air temperature is too high, that is, the cooling capacity of the clean workshop 1 cannot meet the demand, so the second control valve V2 is opened, the medium-temperature chiller 33 is started, and a part of the cooling water flowing out of the cooling tower 31 is transported to the three-medium heat exchanger 32 through the first pipeline G1, and absorbs heat and heats up through the dry coil of the three-medium heat exchanger 32, and reduces the return air temperature; another part of the cooling water is transported to the condenser 331 of the medium-temperature chiller 33 through the second pipeline G2, and absorbs heat and heats up through the condenser 331. The heated cooling water is all dissipated and cooled through the cooling tower 31, and then transported to the three-medium heat exchanger 32 and the condenser 331 to form a cycle. At the same time, the low-temperature refrigerant flowing out of the evaporator 332 flows into the three-medium heat exchanger 32, and the low-temperature refrigerant absorbs heat and heats up through the dry coil of the three-medium heat exchanger 32, and reduces the return air temperature. In this process, the cooling water of the cooling tower 31 and the medium-temperature water flowing out of the evaporator 332 are used to jointly adjust the return air temperature until T1≤Tm1, so that the outlet air temperature of the three-medium heat exchanger 32 meets the target return air temperature, and then the return air and the fresh air meet the cooling demand of the clean workshop 1 after the return.

[0080] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive and therefore specify the presence of stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0081] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0082] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. An air conditioning system, characterized in that: include: Clean room (1); A fresh air unit (2), the output end of which is connected to the clean room (1) and is used to transport outdoor fresh air; as well as A return air conditioning component (3) comprises a cooling tower (31) and a three-medium heat exchanger (32), wherein the cooling tower (31) has a first input end, the input end of the cooling tower (31) is connected to the first output end of the three-medium heat exchanger (32), the output end of the cooling tower (31) is connected to the first input end of the three-medium heat exchanger (32), and the three-medium heat exchanger (32) is connected to the output end of the fresh air unit (2) to adjust the supply air temperature entering the clean workshop (1); If the air conditioning system is operated in a transitional season, the cooling water of the cooling tower (31) is controlled to enter the three-medium heat exchanger (32) and to exchange heat with the return air of the clean workshop (1), so that the cooled air is mixed with the outdoor fresh air and then enters the clean workshop (1).

2. The air conditioning system according to claim 1, characterized in that: The return air conditioning assembly (3) comprises a first pipeline (G1) and a first control valve (V1); the first end of the first pipeline (G1) is connected to the output end of the cooling tower (31); the second end of the first pipeline (G1) is connected to the first input end of the three-medium heat exchanger (32); and the first control valve (V1) is arranged on the first pipeline (G1).

3. The air conditioning system according to claim 2, characterized in that: The return air conditioning assembly (3) comprises: A medium-temperature chiller (33), comprising a condenser (331) and an evaporator (332), wherein the condenser (331) is connected to the cooling tower (31), the input end of the evaporator (332) is connected to the second output end of the three-medium heat exchanger (32), and the output end of the evaporator (332) is connected to the second input end of the three-medium heat exchanger (32); a second pipeline (G2), a first end of which is connected to the output end of the cooling tower (31), and a second end of which is connected to the input end of the condenser (331); and a second control valve (V2), arranged on the second pipeline (G2); The air conditioning system further comprises a first temperature sensor (51) for detecting the outlet air temperature of the three-medium heat exchanger (32); If the outlet air temperature of the three-medium heat exchanger (32) is greater than the target return air temperature, the opening of the first control valve (V1) is controlled to decrease, and the opening of the second control valve (V2) is controlled to increase.

4. The air conditioning system according to claim 3, characterized in that: The return air conditioning component (3) comprises a third pipeline (G3), a first end of the third pipeline (G3) being connected to an output end of the cooling tower (31), a second end of the third pipeline (G3) being connected to a first end of the first pipeline (G1) and a first end of the second pipeline (G2) at the same time, and a first water pump (G31) being arranged on the third pipeline (G3).

5. The air conditioning system according to claim 3, characterized in that: The return air conditioning component (3) comprises a fourth pipeline (G4), a first end of the fourth pipeline (G4) being connected to an output end of the evaporator (332), a second end of the fourth pipeline (G4) being connected to a second input end of the three-medium heat exchanger (32), and a second water pump (G41) being arranged on the fourth pipeline (G4).

6. The air conditioning system according to claim 1, characterized in that: It comprises an air supply channel (4) and an air return channel (5), wherein a first end of the air supply channel (4) is connected to an output end of the fresh air unit (2), and a second end of the air supply channel (4) is connected to the clean room (1); The first end of the return air channel (5) is connected to the clean room (1), and the second end of the return air channel (5) is connected to the first end of the air supply channel (4); The three-medium heat exchanger (32) is arranged on the return air channel (5) so that the air in the clean room (1) can exchange heat with the medium flowing inside the three-medium heat exchanger (32).

7. The air conditioning system according to claim 6, characterized in that: The air supply channel (4) has an air supply section (41), and the air supply section (41) of the air supply channel (4) is provided with a filter unit assembly.

8. The air conditioning system according to claim 6, characterized in that: The air supply channel (4) has an air mixing section (42), the air mixing section (42) of the air supply channel (4) is arranged at a first end of the air supply channel (4), and the air mixing section (42) of the air supply channel (4) is provided with a first temperature and humidity sensor (421).

9. The air conditioning system according to claim 8, characterized in that: A fresh air channel (21) is provided at the output end of the fresh air unit (2); an end of the fresh air channel (21) away from the fresh air unit (2) is connected to the air mixing section (42) of the air supply channel (4); and a second temperature and humidity sensor (211) is provided on the fresh air channel (21).

10. The air conditioning system according to claim 3, characterized in that: comprising a second temperature detection device (G32), wherein the second temperature detection device (G32) is used to detect the outlet water temperature of the cooling tower (31); If the outlet water temperature of the cooling tower (31) is lower than the minimum target inlet water temperature, the first control valve (V1) is controlled to be open and the second control valve (V2) is controlled to be closed.

11. A control method for an air conditioning system, applied to the air conditioning system according to any one of claims 1 to 10, characterized in that: The control method comprises: Obtaining the operating condition of the air conditioning system; If the air conditioning system is operated in a transitional season, the cooling water of the cooling tower (31) is controlled to enter the three-medium heat exchanger (32) for heat exchange, so that the cooled air is mixed with outdoor fresh air and then enters the clean workshop (1).

12. The control method according to claim 11, characterized in that: The air conditioning system comprises a first pipeline (G1), a first control valve (V1), a condenser (331), a second pipeline (G2), a second control valve (V2), an evaporator (332) and a first temperature sensor (51), and the control method comprises: If the outlet air temperature of the three-medium heat exchanger (32) of the air conditioning system is greater than the target return air temperature, the opening of the first control valve (V1) is controlled to decrease, and the opening of the second control valve (V2) is controlled to increase, until the outlet air temperature of the three-medium heat exchanger (32) is less than or equal to the target return air temperature.

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