Air handling units and their multi-stage heating and regeneration fresh air handling systems

Abstract

The application discloses an air handling unit and a fresh air treatment system with multi-stage heating regeneration. The fresh air treatment system comprises a rotary dehumidification device and a plurality of refrigeration cycle units. Condensers of the plurality of refrigeration cycle units are arranged on one side of the rotary dehumidification device, and are used for gradually heating regeneration air. The heated regeneration air is used as a heat source of a regeneration area of the rotary dehumidification device. Evaporators of the plurality of refrigeration cycle units are arranged on the other side of the rotary dehumidification device, and are used for gradually cooling the regeneration air discharged from the regeneration area. The cooled regeneration air is discharged into the atmosphere or is used as another heat source. The application uses condensation heat to gradually heat the regeneration air, and replaces the mode that electricity or steam is used as a heat source for regenerating an adsorbent in the prior art, so that the required energy consumption is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to an air handling unit for a lithium battery workshop and its multi-stage heating and regeneration fresh air handling system. Background Technology

[0002] Many environments have specific requirements for air temperature and humidity, such as large computer rooms, cinemas, and industrial production workshops with high temperature and humidity requirements. Therefore, air conditioning equipment is widely used. For example, the production process of lithium batteries is extremely sensitive to humidity. Moisture can decompose the electrolyte, corrode the electrodes, and damage the separator, leading to a decline in lithium battery performance and even explosions. The lithium battery production process is divided into front-end, mid-end, and back-end stages, all of which have very high humidity control requirements. In the front-end electrode fabrication stage, the humidity requirement for stirring and coating is 2%-20%; in the mid-end cell assembly stage, the dew point temperature requirement for winding and electrolyte injection is -20℃-50℃; and in the back-end packaging and testing stage, the relative humidity requirement for formation and encapsulation is 30%. Therefore, humidity control during the lithium battery production process is crucial.

[0003] Currently, the mainstream dehumidification solution in the industry uses rotary dehumidifiers. These dehumidifiers consist of a dehumidification zone and a regeneration zone, both operating on the same rotating wheel and working alternately. When fresh air passes through the dehumidification zone, it absorbs moisture through the adsorbent, dries, and is then delivered into the room. The adsorbent gradually becomes saturated and rotates to the regeneration zone, where it is purged with hot air to release the adsorbed moisture and regenerate. The regenerated, dried adsorbent returns to the dehumidification zone, while the humid air (regeneration exhaust gas) is discharged outdoors. The regeneration zone requires heat energy; the temperature typically needs to reach 80-150℃ to expel the humid air from the system and maintain the continuous and efficient operation of the dehumidification zone. In existing technologies, the heat source for the regeneration zone is generally electricity or steam, resulting in significant energy consumption and ultimately increasing product costs.

[0004] Therefore, how to reduce the power consumption of the regeneration process is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0005] This invention proposes an air handling unit and its multi-stage heating and regeneration fresh air handling system to solve the technical problem of high energy consumption in existing fresh air handling processes.

[0006] The technical solution adopted in this invention is to design a multi-stage heating and regeneration fresh air treatment system, including a rotary dehumidifier and multiple sets of refrigeration cycle units. The condenser group of the multiple sets of refrigeration cycle units is located on one side of the rotary dehumidifier to heat the regeneration air step by step. The heated regeneration air serves as the heat source for the regeneration zone of the rotary dehumidifier. The evaporator group of the multiple sets of refrigeration cycle units is located on the other side of the rotary dehumidifier to cool the regeneration air discharged from the regeneration zone step by step. The cooled regeneration air is discharged into the atmosphere or used as other heat sources.

[0007] In one embodiment, the multi-stage heating and regeneration fresh air treatment system includes four sets of refrigeration cycle units. The condenser groups of the refrigeration cycle units are arranged in order of increasing condensation temperature, with the outlet of the condenser with the highest condensation temperature facing the air inlet of the regeneration zone. The evaporator groups of the four sets of refrigeration cycle units are arranged in order of decreasing evaporation temperature, with the air inlet of the evaporator with the highest evaporation temperature facing the regeneration air outlet of the regeneration zone.

[0008] Preferably, the four refrigeration cycle units are a low-temperature refrigeration cycle unit, a medium-temperature first refrigeration cycle unit and a medium-temperature second refrigeration cycle unit, and a cascade refrigeration cycle unit, wherein the cascade refrigeration cycle unit is composed of a medium-temperature compressor unit and a high-temperature compressor unit.

[0009] Preferably, the condenser of the low-temperature refrigeration cycle unit serves as a preheater for the regenerated air, and the evaporator is located at the fresh air outlet of the rotary dehumidifier to cool the dehumidified fresh air; the condenser of the first refrigeration cycle unit serves as the first condenser and is located after the preheater; the condenser of the second refrigeration cycle unit serves as the second condenser and is located after the first condenser; and the condenser of the medium-temperature compressor unit in the cascade refrigeration cycle unit serves as the third condenser and is located after the second condenser.

[0010] Preferably, the evaporator of the high-temperature compressor unit of the cascade refrigeration cycle unit is located at the outlet of the regeneration zone as the first evaporator, the evaporator of the second refrigeration cycle unit is located after the first evaporator as the second evaporator, and the evaporator of the first refrigeration cycle unit is located after the second evaporator as the third evaporator.

[0011] Furthermore, the rotary dehumidifier is equipped with a surface cooler at the front end of the fresh air inlet. The fresh air is cooled by the surface cooler before entering the rotary dehumidifier for dehumidification. The dehumidified fresh air is then cooled by the evaporator of the low-temperature refrigeration cycle unit before being sent into the room.

[0012] Preferably, the rotary dehumidifier rotates eight times per minute, and the ratio of the dehumidification zone to the regeneration zone is three to one.

[0013] Preferably, filters are provided at the inlet of the fresh air, the inlet of the regenerated air, and the outlet of the regeneration zone.

[0014] In another embodiment, the two fresh air handling devices are connected in series. Fresh air is sent into the room after being dehumidified in two stages. Part of the fresh air after being dehumidified by the secondary rotary dehumidifier is used as the regeneration air of the secondary rotary dehumidifier.

[0015] Preferably, the refrigeration cycle unit adopts a modular classification for easy installation, wherein the condenser group is a module, the evaporator group is a module, and the compressor group is a module.

[0016] The present invention also proposes an air handling unit, which includes the above-mentioned multi-stage heating and regeneration fresh air handling system.

[0017] Compared with the prior art, the technical solution proposed in this invention has the following advantages:

[0018] 1. This invention uses condensation heat to heat regenerated air in stages, replacing the existing electric or steam heating methods, which significantly reduces the energy consumption required for production. The replacement of electric heating alone results in an energy saving rate of over 50%, and the overall energy saving rate of the machine is no less than 45%.

[0019] 2. This invention adopts a mode combining low-temperature, medium-temperature and high-temperature refrigeration cycles to heat regenerated air in stages. The energy consumption of the high-temperature cycle accounts for a very small proportion, with most of the energy consumption occurring in the medium- and low-temperature cycles. This ensures the high energy efficiency ratio of the system, significantly reduces energy consumption, and improves the reliability of the unit operation. In addition, the power of multiple compressors is miniaturized, enabling precise adjustment and avoiding large fluctuations in the start-up and shutdown power of high-power compressors.

[0020] 3. This invention employs a cascade refrigeration cycle and uses intelligent control technology to optimally match the load fluctuations and flow regulation on both sides of the cascade to ensure stable system operation;

[0021] 4. This invention uses the evaporator of the low-temperature circulating unit to cool the dehumidified fresh air, saving the cost and energy consumption required for a separate surface cooler. Attached Figure Description

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments, wherein:

[0023] Figure 1 This is a schematic diagram of existing fresh air treatment and adsorbent regeneration;

[0024] Figure 2 This is a system diagram of an embodiment of the fresh air treatment system proposed in this invention;

[0025] Figure 3This is a system diagram of another embodiment of the fresh air treatment system proposed in this invention.

[0026] The components include: 1. Rotary dehumidifier, 2. Condenser group, 3. Evaporator group, 4. Filter, 5. First surface cooler, 6. Dehumidification zone, 7. Regeneration zone, 8. Second surface cooler, 9. Fan, 10. Low-temperature refrigeration cycle unit, 11. First refrigeration cycle unit, 12. Second refrigeration cycle unit, 13. Medium-temperature compressor unit, 14. High-temperature compressor unit, 15. Preheater, 16. Electric heater, 17. Evaporator-condenser, 21. First condenser, 22. Second condenser, 23. Third condenser, 31. First evaporator, 32. Second evaporator, and 33. Third evaporator. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the invention and do not constitute a limitation thereof.

[0028] The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of components and steps set forth in these embodiments do not limit the scope of protection of the invention.

[0029] While techniques, methods, and apparatus known to those skilled in the art are not discussed in detail herein, such techniques, methods, and apparatus should be considered part of this specification where appropriate. Any specific values ​​in this specification should be interpreted as merely exemplary and not as limiting the invention.

[0030] For ease of description, the terms used in the specification to describe position, such as "above", "to the left", "in front", etc., are only used to describe the spatial positional relationship between a component and other components in the embodiment shown in the figure. When the position of the component is different, the relative position will change. Therefore, the positional relationship of the embodiment in the figure should not be construed as limiting the present invention.

[0031] Furthermore, it should be noted that the use of terms such as "first" and "second" in the specification is merely for distinguishing similar components and does not imply any order of precedence. Therefore, it should not be construed as limiting the scope of protection of this invention.

[0032] Figure 1This is a schematic diagram of existing fresh air treatment and adsorbent regeneration. Fresh air passes through filter 4 and fan 9 into the dehumidification zone 6 of the rotary dehumidifier 1 for dehumidification, and the dehumidified fresh air is then sent into the room. Regenerated air passes through filter 4 and electric heater 16 before being sent to the regeneration zone 7 of the rotary dehumidifier 1 to regenerate the adsorbent. The regenerated adsorbent is then returned to dehumidification zone 6 for operation. As mentioned in the background section, this method, which relies on electricity as the heat source for adsorbent regeneration, consumes a huge amount of energy.

[0033] The concept of this invention is to replace the heat source for regenerating the adsorbent by electric heating or steam heating with the condensation heat of the refrigeration cycle, thereby reducing energy consumption. At the same time, the regenerated air is heated in stages to reduce the energy consumption of the compressor unit and improve the energy efficiency ratio of the whole system.

[0034] The multi-stage heating and regeneration fresh air treatment system proposed in this invention includes a rotary dehumidifier and multiple sets of refrigeration cycle units. The condenser group of the multiple sets of refrigeration cycle units is located on one side of the rotary dehumidifier to heat the regeneration air step by step. The heated regeneration air serves as the heat source for the regeneration zone of the rotary dehumidifier. The evaporator group of the multiple sets of refrigeration cycle units is located on the other side of the rotary dehumidifier to cool the regeneration air discharged from the regeneration zone step by step. The cooled regeneration air is discharged into the atmosphere or used as other heat sources.

[0035] Figure 2 This is a system diagram of an embodiment of the fresh air handling system proposed in this invention. The fresh air handling system includes a rotary dehumidifier 1, a condenser assembly 2 located on the left side of the rotary dehumidifier, and an evaporator assembly 3 located on the right side of the rotary dehumidifier. Fresh air is sequentially delivered into the room after passing through a filter (not shown), a first surface cooler 5, the dehumidification zone 6 of the rotary dehumidifier 1, and a second surface cooler 8. A fan (not shown) is installed in the fresh air duct. Regenerated air is sequentially discharged into the atmosphere or used for other purposes after passing through a filter (not shown), the condenser assembly 2, the regeneration zone 7 of the rotary dehumidifier 1, and the evaporator assembly 3. A fan (not shown) is installed in the regenerated air duct.

[0036] In this embodiment, four refrigeration cycle units are included: a low-temperature refrigeration cycle unit 10, a medium-temperature first refrigeration cycle unit 11 and a second refrigeration cycle unit 12, and a cascade refrigeration cycle unit. The cascade refrigeration cycle unit includes a medium-temperature compressor unit 13, a third condenser 23, an evaporator-condenser 17, a high-temperature compressor unit 14, and a first evaporator 31.

[0037] The condenser of the low-temperature refrigeration cycle unit 10 serves as the preheater 15, and the evaporator serves as the second surface cooler 8, located at the fresh air outlet of the rotary dehumidifier 1 to cool the dehumidified fresh air. The condenser of the first refrigeration cycle unit 11 serves as the first condenser 21, located after the preheater 15. The condenser of the second refrigeration cycle unit serves as the second condenser 22, located after the first condenser 21. The condenser of the medium-temperature compressor unit 13 in the cascade refrigeration cycle unit serves as the third condenser 23, located after the second condenser 22. The evaporator of the high-temperature compressor unit of the cascade refrigeration cycle unit serves as the first evaporator 31, located at the outlet of the regeneration zone. The evaporator of the second refrigeration cycle unit serves as the second evaporator 32, located after the first evaporator 31. The evaporator of the first refrigeration cycle unit serves as the third evaporator 33, located after the second evaporator 32.

[0038] The condenser groups of the four refrigeration cycle units are arranged in order of increasing condensing temperature, with the outlet of the condenser with the highest condensing temperature facing the air inlet of the regeneration zone 7. Figure 2 As can be seen, the condensing temperatures of preheater 15, first condenser 21, second condenser 22, and third condenser 23 are 63℃, 84℃, 95℃, and 115℃, respectively. The evaporators of the four refrigeration cycle units are arranged in descending order of evaporation temperature. The air inlet of the evaporator with the highest evaporation temperature faces the regeneration air outlet of regeneration zone 7. The evaporation temperatures of the first evaporator 31, second evaporator 32, and third evaporator 33 are 80℃, 65℃, and 50℃, respectively. Of course, the above condensing and evaporation temperatures are not fixed and can be changed according to the regeneration temperature requirements of different adsorbents.

[0039] exist Figure 2 In the embodiment shown, the rotary dehumidifier rotates eight times per minute, and the ratio of the dehumidification zone to the regeneration zone is three to one.

[0040] The steps for fresh air dehumidification are: fresh air -- first surface cooler cooling -- rotary dehumidification zone dehumidification -- second surface cooler cooling -- delivered into the room.

[0041] The steps for regenerating air are: regenerated air -- heated by a multi-stage condenser -- sent to the rotary regeneration zone to regenerate the adsorbent -- heat recovery by a multi-stage evaporator -- discharged into the atmosphere.

[0042] In this invention, condensation heat is used instead of electric heating or steam heating, and the condenser is used to heat the regenerated air in stages. This takes into account both the high energy efficiency ratio of medium and low temperature compression and the high temperature output of high temperature compression. In this invention, high temperature compression accounts for 25% of the system, and the other 75% belongs to medium and low temperature compression, resulting in a relatively high overall system energy efficiency.

[0043] In this invention, the high-temperature compression section adopts a cascade compression cycle, which has an ultra-wide operating range and a condensation temperature as high as 150°C. Through intelligent control technology, the load fluctuations and flow regulation on both sides of the cascade can be optimally matched to ensure the stable operation of the system.

[0044] In this invention, the evaporator in the low-temperature refrigeration cycle is used as the surface cooler after the fresh air is dehumidified to cool the fresh air, thereby reducing the temperature of the fresh air after dehumidification and saving the cost of installing a separate surface cooler.

[0045] In this invention, the regenerated waste heat is effectively recovered, while avoiding the problem that heat recovery devices commonly used in the market that recover both sensible and latent heat are difficult to recover heat from high humidity air.

[0046] It should be noted that the present invention is not limited to using four sets of refrigeration compression cycle units. Instead, the appropriate unit can be selected based on the temperature required for the regeneration of the adsorbent material actually used. The condensation temperature and evaporation temperature can also be adjusted according to the number of refrigeration units selected, as long as the staged heating of the regenerated air is met to achieve the purpose of regenerating the adsorbent material.

[0047] The air handling unit with a multi-stage heating and regeneration fresh air treatment system manufactured according to this invention has been commissioned to the Shenzhen Institute of Metrology and Quality Inspection for on-site testing. The test data is shown in the table below:

[0048] .

[0049] Note: Total power includes heat pump input power, fan power, and rotor power.

[0050] Energy saving rate calculation process: This system replaces the original rotary dehumidifier unit, which uses electric heating (electric-thermal conversion rate is assumed to be 100%, i.e., COP). 原 (Using 1.00), the energy saving rate is calculated by comparing the electricity consumption per unit of heat:

[0051] ;

[0052] Test results: During the on-site test on June 24, 2025, the reheat efficiency ratio of the air handling unit was 1.90. Compared with the original rotary dehumidifier unit (with an electrothermal conversion efficiency of 100%), the energy saving rate of this product's air handling unit is 47.4%.

[0053] Figure 3 This is a system diagram of another embodiment of the fresh air handling system proposed in this invention. This embodiment employs a two-stage dehumidification and two-stage regeneration system, designed for environments with very high humidity requirements.

[0054] Unlike the first embodiment, two sets of fresh air handling systems are used in series to meet the requirements of particularly high humidity. In this embodiment, fresh air undergoes primary dehumidification by the first rotary dehumidifier 1, then is cooled by the second surface cooler 8 (the function of the second surface cooler is the same as that of the first surface cooler 5 before primary dehumidification), and then enters the second rotary dehumidifier 1 for secondary dehumidification. The fresh air after secondary dehumidification is cooled by the second surface cooler 8 and then sent into the room. The two second surface coolers 8 are connected in parallel, and the cooling capacity is provided by the low-temperature refrigeration cycle unit 10. Part of the fresh air that has undergone secondary dehumidification is used as regeneration air. After being heated in stages by the condenser group 2, it enters the regeneration zone of the second rotary dehumidifier for primary regeneration. The primary regeneration air is heated by the condenser group located between the regeneration zones of the two rotary dehumidifiers, and then enters the regeneration zone of the first rotary dehumidifier 1 for secondary regeneration. The waste heat generated during secondary regeneration is recovered by the evaporator group 3 and then discharged into the atmosphere. In the second embodiment, the staged heating condenser group between the two rotary dehumidifiers can be connected in parallel with the condenser group of the first rotary dehumidifier, without the need for a separate heat source.

[0055] To facilitate the retrofitting of existing rotary dehumidifier units, the heat source replacement components in this invention can be modularly designed. This eliminates the need for major modifications to the original rotary dehumidifier equipment; only the electric or steam heating heat source components need to be replaced with modules. For example, the compressor unit of the refrigeration cycle unit can be considered as one module, the condenser unit as another, and the evaporator unit as yet another. These modules can be placed directly on top of the original fresh air handling system and connected directly to the fresh air duct and regenerated air duct. This simplifies installation and avoids damaging the original rotary dehumidifier.

[0056] The above description is merely a specific embodiment of the present invention. It should be noted that any modifications, equivalent substitutions, and variations made within the spirit and framework of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-stage heat regeneration process fresh air handling system comprising a rotary dehumidification device, characterized by, Further comprising four sets of refrigeration cycle units, condenser groups of the four sets of refrigeration cycle units are arranged in order of condensing temperature from low to high on one side of the rotary dehumidification device, to heat the regeneration air step by step, the heated regeneration air is used as the heat source of the regeneration area of the rotary dehumidification device, evaporator groups of the four sets of refrigeration cycle units are arranged in order of evaporation temperature from high to low on the other side of the rotary dehumidification device, to cool the regeneration air discharged from the regeneration area step by step, and the cooled regeneration air is discharged into the atmosphere; the four sets of refrigeration cycle units respectively use a low-temperature refrigeration cycle unit, a first refrigeration cycle unit and a second refrigeration cycle unit of medium temperature, and a cascade refrigeration cycle unit, the cascade refrigeration cycle unit is composed of a medium-temperature compressor group and a high-temperature compressor group.

2. The fresh air handling system of claim 1, wherein, The condenser of the low-temperature refrigeration cycle unit is used as a preheater for the regeneration air, and the evaporator is arranged at the outlet of the fresh air of the rotary dehumidification device to cool the dehumidified fresh air. The condenser of the first refrigeration cycle unit is used as a first condenser and arranged behind the preheater. The condenser of the second refrigeration cycle unit is used as a second condenser and arranged behind the first condenser. The condenser of the medium-temperature compressor group in the cascade refrigeration cycle unit is used as a third condenser and arranged behind the second condenser.

3. The fresh air handling system of claim 1, wherein, The evaporator of the high-temperature compressor group of the cascade refrigeration cycle unit is used as a first evaporator and arranged at the outlet of the regeneration area, the evaporator of the second refrigeration cycle unit is used as a second evaporator and arranged behind the first evaporator, and the evaporator of the first refrigeration cycle unit is used as a third evaporator and arranged behind the second evaporator.

4. The fresh air handling system of claim 1, wherein, A surface air cooler is arranged at the front end of the fresh air inlet of the rotary dehumidification device, and the fresh air is cooled by the surface air cooler and then enters the rotary dehumidification device for dehumidification, and the dehumidified fresh air is cooled by the evaporator of the low-temperature refrigeration cycle unit and then sent into the room.

5. The fresh air handling system of claim 1, wherein, The rotary dehumidification device rotates eight times per minute, and the ratio of the dehumidification area to the regeneration area is three to one.

6. The fresh air handling system according to any one of claims 1-5, wherein, The two fresh air treatment systems are arranged in series, the fresh air is dehumidified by two stages and then sent into the room, and part of the fresh air dehumidified by the second stage is used as the regeneration air of the second rotary dehumidification device.

7. The fresh air handling system of claim 1, wherein, The four sets of refrigeration cycle units adopt modular classification for easy installation, in which the condenser groups are used as a module, the evaporator groups are used as a module, and the compressor groups are used as a module.

8. An air handling unit, comprising: The fresh air treatment system of any one of claims 1-7 is included.

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