Deep dehumidification energy-saving air conditioning system for electronic clean room

Abstract

The utility model discloses a deep dehumidification energy-saving air conditioning system of an electronic clean room, which comprises a clean room air circulation flow channel, a fresh air handling unit and a return air processing device, the clean room air circulation flow channel comprises an upper technical interlayer and a return air passageway, and a direct expansion machine system is embedded in the fresh air handling unit. The return air treatment device cools return air of the return air passageway and then feeds the return air into the upper technical interlayer, the return air is mixed with fresh air fed into the upper technical interlayer by the fresh air handling unit, and heat recovered by the return air treatment device exchanges heat with a fresh air ethylene glycol heating coil in the fresh air handling unit. The deep dehumidification energy-saving air conditioning system for the electronic clean room can meet the control requirements of the temperature and the humidity of the electronic clean room under different seasonal conditions, meanwhile, heat of the direct expansion machine condenser and the return air processing device can be effectively utilized, and the reheat requirement of the fresh air ethylene glycol heating coil is lowered.

Description

Technical Field

[0001] This utility model relates to the field of air conditioning technology, and in particular to an electronic cleanroom deep dehumidification energy-saving air conditioning system. Background Technology

[0002] Currently, air conditioning systems in electronic cleanrooms commonly employ a configuration of a mains air handling unit (MAU), a direct current cooling coil (DCC), and a fan filter unit (FFU). The MAU processes outdoor fresh air, handling the indoor humidity load. In summer, it cools and dehumidifies the fresh air; in winter, it heats and humidifies it. The treated fresh air is directly supplied to the upper mezzanine of the cleanroom, mixing with the indoor return air, and then filtered by the FFU before being delivered to the work area. Return air passes through the mezzanine duct, is cooled by the DCC above the duct, and returns to the upper mezzanine. The sensible heat load is handled by the DCC, which typically provides cooling year-round. The FFU circulates air to achieve the required air exchange rate for cleanliness. The MAU controls indoor humidity, while the DCC controls indoor temperature, enabling independent and precise control of both.

[0003] Because these cleanrooms have specific cleanliness requirements, even when meeting indoor environmental control requirements, the reheating of the MAU after condensation dehumidification creates a heat-cold offsetting problem, resulting in high energy consumption. Furthermore, in electronic cleanrooms, MAUs typically use chilled water coils for dehumidification, generally achieving humidity control requirements of around 45%. However, for clean spaces with lower relative humidity requirements (such as 30%–40%), chilled water coils cannot meet the dehumidification needs. Utility Model Content

[0004] Purpose of the utility model: The purpose of this utility model is to provide a low-energy-consumption deep dehumidification and energy-saving air conditioning system for electronic cleanrooms, which can meet the temperature and humidity control requirements of electronic cleanrooms under different seasonal conditions and reduce the reheating demand of reheat coils.

[0005] Technical Solution: To achieve the above objectives, the present invention provides an electronic cleanroom deep dehumidification and energy-saving air conditioning system, comprising a cleanroom air circulation channel, a fresh air unit, and a return air treatment device. The cleanroom air circulation channel includes an upper technical interlayer and a return air duct. The return air treatment device cools the return air from the return air duct and then sends it into the upper technical interlayer, where it mixes with the fresh air sent into the upper technical interlayer by the fresh air unit. The heat recovered by the return air treatment device is exchanged with the fresh air glycol heating coil in the fresh air unit.

[0006] The return air treatment device includes a return air heat recovery unit, which is located outside the air circulation channel and includes a return air fan and a return air glycol cooling coil.

[0007] The return air ethylene glycol cooling coil exchanges heat with the fresh air ethylene glycol heating coil through the ethylene glycol circulation pump 33.

[0008] The return air treatment device also includes a dry coil unit, which consists of multiple sets of dry coils connected in parallel within the upper technical interlayer, specifically located at the channel opening that connects to the return air duct.

[0009] The fresh air handling unit is equipped with a direct expansion machine system.

[0010] The direct expansion machine system includes an evaporator, a condenser, and a compressor, with the evaporator and condenser connected by an expansion valve.

[0011] The compressor is located outside the frame of the fresh air handling unit.

[0012] The fresh air handling unit includes a frame with a fresh air inlet and a fresh air outlet at both ends. Between the fresh air inlet and the fresh air outlet, a pre-filter, a medium-efficiency filter, a heating coil, a pre-cooling coil, a spray humidifier, a surface cooling coil, a direct expansion evaporator, a direct expansion valve, a direct expansion condenser, a fresh air glycol heating coil, a fresh air blower, and a high-efficiency filter are arranged in sequence. It also includes a compressor. The evaporator and condenser are connected to the compressor and the expansion valve to form a direct expansion system.

[0013] The fresh air supply fan is a variable frequency fan.

[0014] Beneficial effects: The present invention has the following advantages: 1. The electronic cleanroom deep dehumidification energy-saving air conditioning system of the present invention can perform deep dehumidification by using a fresh air unit, which is suitable for electronic cleanroom environments with lower humidity requirements. At the same time, it integrates multiple air handling functions such as filtration, heating, cooling, dehumidification, humidification and air supply, which can meet the temperature and humidity control requirements under different seasonal conditions.

[0015] 2. The fresh air handling unit further integrates the condenser of the direct expansion turbine into the fresh air handling unit, making full use of the condenser's heat and reducing the reheat requirement of the heating coil, thereby achieving the purpose of energy saving and cost reduction.

[0016] 3. The aforementioned deep dehumidification and energy-saving air conditioning system for electronic cleanrooms utilizes a return air treatment device to effectively recover heat from the return air. This heat is then exchanged with the heating coil in the fresh air handling unit via a circulating pump, enabling the fresh air handling unit to reheat the fresh air using the heat recovered by the return air treatment device. This saves energy consumption for fresh air reheating and achieves optimized energy utilization. Attached Figure Description

[0017] Figure 1 This is a structural block diagram of the deep dehumidification and energy-saving air conditioning system for electronic cleanrooms described in this embodiment. Detailed Implementation

[0018] The technical solution of this utility model will be described in detail below with reference to the embodiments and accompanying drawings.

[0019] like Figure 1 As shown, this utility model embodiment provides an electronic cleanroom deep dehumidification energy-saving air conditioning system, including an air circulation channel 1, a fresh air unit 2, and a return air treatment device 3.

[0020] The air circulation channel 1 includes a lower technical interlayer 11, a return air duct 12, and an upper technical interlayer 13 connected in sequence. The upper technical interlayer 13 is connected to the clean area 14 via a fan filter unit 15, and the lower technical interlayer 11 is connected to the raised floor 16 of the clean area 14. The fresh air unit 2 is connected to the upper technical interlayer 13 via a fresh air duct 4. The return air duct 12 is used to transport the air in the lower technical interlayer 11 back to the upper technical interlayer 13, where it is mixed with the fresh air processed by the fresh air unit 2 and the return air cooled by the return air treatment device 3. The mixed air then re-enters the clean area 14 through the fan filter unit 15.

[0021] The fresh air handling unit 2 includes a frame with a fresh air inlet 201 and a fresh air outlet 202 at both ends. Between the fresh air inlet 201 and the fresh air outlet 202, a pre-filter 203, a medium-efficiency filter 204, a heating coil 205, a pre-cooling coil 206, a spray humidifier 207, a surface cooling coil 208, a direct expansion evaporator 209, a direct expansion valve 214, a direct expansion condenser 210, a fresh air glycol heating coil 211, a fresh air supply fan 212, and a high-efficiency filter 213 are sequentially arranged. Outside the frame, a compressor 215 is also included. The evaporator 209 and the condenser 210 are connected to the compressor 215 and the expansion valve 214 to form a direct expansion system.

[0022] Among them, the pre-filter 203 and the medium-efficiency filter 204 can filter particulate pollutants in the air. The heating coil 205 preheats the filtered fresh air. The pre-cooling coil 206 is used to pre-cool the fresh air. The spray humidifier 207 is used to adjust the humidity of the fresh air. The surface cooling coil 208 is used to further cool the fresh air to achieve deep dehumidification. The evaporator 209, as part of the direct expansion unit system, is used to absorb heat from the fresh air to achieve dehumidification. The condenser 210 releases the heat absorbed by the evaporator 209 and the heat generated when the compressor compresses the refrigerant into the surrounding environment. The fresh air glycol heating coil 211 is used to reheat the dehumidified fresh air to achieve a suitable supply air temperature. The fresh air supply fan 212 sends the treated fresh air into the technical interlayer 13 through the fresh air duct 4. The high-efficiency filter 213 is used for final air filtration to ensure the air quality of the clean room.

[0023] The chilled water of the chiller unit is fed into the precooling coil 206 and the surface cooling coil 208. The required cooling capacity of the direct expansion evaporator 209 should be configured according to the absolute humidity of the electronic clean room and the air condition at the outlet of the surface cooling coil 208.

[0024] The return air handling unit 3 is located on the airflow path within the air circulation channel 1. The return air handling unit 3 includes a dry coil assembly 31 and a return air heat recovery unit 32. The dry coil assembly 31 includes multiple sets of dry coils connected in parallel within the upper technical interlayer 13, specifically located at the opening of the channel communicating with the return air interlayer 12. The return air heat recovery unit 32 is located outside the air circulation channel 1 and includes a return air glycol cooling coil 321 and a return air fan 322. The return air fan 322 draws return air from the return air interlayer 12, and the return air glycol cooling coil 321 cools the return air and delivers it into the upper technical interlayer 13.

[0025] An ethylene glycol circulation pump 33 is provided between the fresh air ethylene glycol heating coil 211 and the return air ethylene glycol cooling coil 321, so that the ethylene glycol solution circulates between the two coils and exchanges heat with the fresh air and return air respectively.

[0026] The return air treatment device 3 is mainly used to treat the return air that comes out of the lower technical interlayer 11 and enters the return air duct 12. When part of the return air enters the upper technical interlayer 13 from the return air duct 12, it is cooled by the dry coil group 31 set in the upper technical interlayer 13, and then mixed with the fresh air treated by the fresh air unit 2 and enters the clean area 14. The other part is heat recovered by the return air fan 322 and the return air glycol cooling coil 321 of the return air heat recovery unit 32, and the return air temperature is reduced, so that it is sent into the upper technical interlayer 13.

[0027] The return air volume used for heat recovery in the return air duct 12 is determined by the reheat capacity of the fresh air glycol heating coil 211 and the outlet air temperature of the dry coil group 31.

[0028] The return air treatment device described in this embodiment utilizes the return air heat recovery unit 32 to effectively recover heat from the return air. Then, through the ethylene glycol circulation pump 33, the fresh air ethylene glycol heating coil 211 in the fresh air handling unit 2 can use the heat recovered from the return air ethylene glycol cooling coil 321 to reheat the fresh air, saving energy consumption for fresh air reheating and achieving optimized energy utilization. Furthermore, the fresh air handling unit undertakes part of the indoor cooling load, reducing the cooling load of the original direct current cooling coil (DCC). This reduces the number of DCC coils and optimizes the selection of chiller units, effectively reducing initial investment.

[0029] Furthermore, the fresh air handling unit described in this embodiment integrates multiple air treatment functions such as filtration, heating, cooling, dehumidification, and humidification, which can meet the air conditioning needs under different seasons and operating conditions. In summer, when temperature and humidity are typically high, it is necessary to cool and dehumidify the fresh air. In this case, the evaporator of the direct expansion compressor system can achieve deep dehumidification, making it particularly suitable for electronic cleanrooms with extremely high humidity requirements. In winter, when temperature and humidity are typically low, it is necessary to heat the fresh air. For very low humidity conditions, humidification is also required. Therefore, the direct expansion compressor system can be shut down, reducing energy consumption and achieving energy-efficient operation of the unit.

[0030] Under summer operating conditions, fresh air enters through fresh air inlet 201, and after passing through pre-filter 203 and medium-efficiency filter 204 to filter out some impurities, it undergoes preliminary cooling through pre-cooling coil 206, followed by cooling and dehumidification through surface cooling coil 208. Using 7°C chilled water, the fresh air is treated to a moisture content of approximately 7.4 g / kg, and the temperature is reduced to approximately 10°C. For spaces with higher dehumidification requirements, such as spaces requiring a relative humidity of 30%–40%, the direct expansion compressor system operates, and the fresh air can further pass through evaporator 209 for dehumidification and cooling, further reducing the moisture content to approximately 5.7 g / kg and the temperature to approximately 6.5°C. The fresh air is then heated by condenser 210, raising the temperature to approximately 11°C. In order to meet the requirements of the fresh air outlet temperature, the fresh air after passing through the condenser 210 can be heated to the temperature required in the electronic clean room by the fresh air glycol heating coil 211. The reheat capacity of the fresh air glycol heating coil 211 is determined by the fresh air outlet temperature of the condenser 210 and the required temperature in the electronic clean room. Finally, after passing through the fresh air supply fan 212 and the high-efficiency filter 213, the fresh air is delivered to the upper technical interlayer 13 of the air circulation channel 1 through the fresh air outlet 202.

[0031] In the upper technical interlayer 13, fresh air and return air mix and enter the clean area 14 through the fan filter unit. The air in the clean area 14 enters the lower technical interlayer 11 to form return air, which then re-enters the upper technical interlayer 13 through the return air duct 12. During this process, the return air treatment device 3 processes the return air. Part of the return air enters the upper technical interlayer 13 and is cooled by the dry coil group 31 before mixing with the fresh air. The other part is cooled by the return air fan 322 and the return air glycol cooling coil 321 of the return air heat recovery unit 3 before entering the upper technical interlayer 13 to mix with the fresh air. The return air glycol cooling coil 321 exchanges heat with the fresh air glycol heating coil 211 in the fresh air unit 2 through the glycol circulation pump 33, so that the fresh air glycol heating coil 211 can recover the heat of the return air.

[0032] Under the above operating conditions, the fresh air is first treated to a certain humidity level using the pre-cooling coil 206 and the surface cooling coil 208, and then the humidity level is further reduced by the evaporator 209. At the same time, the heat released by the condenser 210 is fully utilized, which can further reduce the reheat requirement of the fresh air glycol heating coil 211.

[0033] In winter operation, fresh air enters through fresh air inlet 201, and after passing through pre-filter 203 and medium-efficiency filter 204 to filter out some impurities, it is heated by heating coil 205. The heating amount is determined according to the outdoor air conditions and the humidity requirements of the electronic cleanroom. After passing through spray humidifier 207 for cooling and humidification, it reaches a saturated humid air state. In order to meet the fresh air outlet temperature requirements, the fresh air after being cooled and humidified by spray humidifier 207 can pass through fresh air glycol heating coil 211 to heat the fresh air to the temperature required in the electronic cleanroom. Finally, after passing through fresh air fan 212 and high-efficiency filter 213, the fresh air is delivered to the upper technical interlayer 13 of air circulation channel 1 through fresh air outlet 202.

[0034] In winter, the return air treatment method is the same as in summer.

Claims

1. An electronic cleanroom deep dehumidification energy-saving air conditioning system, comprising a cleanroom air circulation channel (1), a fresh air unit (2), and a return air treatment device (3), wherein the cleanroom air circulation channel (1) comprises an upper technical interlayer (13) and a return air duct (12), characterized in that, The return air treatment device (3) cools down the return air in the return air duct (12) and sends it into the upper technical interlayer (13) to mix with the fresh air sent into the upper technical interlayer (13) by the fresh air unit (2). The heat recovered by the return air treatment device (3) is exchanged with the fresh air glycol heating coil (211) in the fresh air unit (2).

2. The deep dehumidification and energy-saving air conditioning system for electronic cleanrooms according to claim 1, characterized in that, The return air treatment device (3) includes a return air heat recovery unit (32), which is located outside the air circulation channel (1) and includes a return air fan (322) and a return air glycol cooling coil (321).

3. The deep dehumidification and energy-saving air conditioning system for electronic cleanrooms according to claim 2, characterized in that, The return air ethylene glycol cooling coil (321) exchanges heat with the fresh air ethylene glycol heating coil (211) through an ethylene glycol circulation pump (33).

4. The deep dehumidification and energy-saving air conditioning system for electronic cleanrooms according to claim 2, characterized in that, The return air treatment device (3) also includes a dry coil group (31), which includes multiple groups of dry coils arranged in parallel in the upper technical interlayer (13), specifically arranged at the channel opening connected to the return air duct (12).

5. The deep dehumidification and energy-saving air conditioning system for electronic cleanrooms according to claim 1, characterized in that, The fresh air handling unit (2) is equipped with a direct expansion machine system.

6. The deep dehumidification and energy-saving air conditioning system for electronic cleanrooms according to claim 5, characterized in that, The direct expansion machine system includes an evaporator (209), a condenser (210), and a compressor (215). The evaporator (209) and the direct expansion machine condenser (210) are connected by an expansion valve (214).

7. The deep dehumidification and energy-saving air conditioning system for electronic cleanrooms according to claim 6, characterized in that, The compressor (215) is located outside the frame of the fresh air handling unit (2).

8. The deep dehumidification and energy-saving air conditioning system for electronic cleanrooms according to claim 1, characterized in that, The fresh air handling unit (2) includes a frame with a fresh air inlet (201) and a fresh air outlet (202) at both ends. Between the fresh air inlet (201) and the fresh air outlet (202), a primary filter (203), a medium-efficiency filter (204), a heating coil (205), a pre-cooling coil (206), a spray humidifier (207), a surface cooling coil (208), a direct expansion evaporator (209), a direct expansion valve (214), a direct expansion condenser (210), a fresh air glycol heating coil (211), a fresh air blower (212), and a high-efficiency filter (213) are arranged in sequence. It also includes a compressor (215). The evaporator (209) and the condenser (210) are connected to the compressor (215) and the expansion valve (214) to form a direct expansion system.

9. The deep dehumidification and energy-saving air conditioning system for electronic cleanrooms according to claim 8, characterized in that, The fresh air supply fan (212) is a variable frequency fan.

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