Air Compression Pretreatment System

Abstract

The air compression pretreatment system includes a dehumidified air duct (1), a heat recovery module (27), and a conditioned air duct (3). The dehumidified air duct (1) is located upstream of an air compressor (5) and includes a dehumidifying wheel (19). The heat recovery module (27) includes a first regenerative air duct (2). A heat exchanger (4) and an air compressor (5) are connected in series upstream of the first regenerative air duct (2). The conditioned air duct (3) and the dehumidified air duct (1) form a circulation air duct. When the air compressor (5) operates at a variable frequency, the amount of air in the dehumidified air duct (1) and the amount of air in the conditioned air duct (3) are dynamically balanced. This reduces the operating energy consumption of the air compression pretreatment system, resulting in more stable and energy-saving operation.

Description

[Technical Field]

[0001] This application claims priority from Chinese Patent Application No. 2022116430502, filed on December 20, 2022, which is incorporated by reference in its entirety. FIELD OF THE INVENTION This application relates to the field of air treatment, for example, to air compression pretreatment systems. [Background technology]

[0002] Compressed air is the second largest power source in industry and plays an important role in industrial production. As industrial structure becomes more advanced, industrial production is shifting to a more intelligent and precise production mode, not only is the application of compressed air becoming more widespread, but the requirements for compressed air quality are also becoming higher. Ultra-low dew point, clean, oil-free compressed air is becoming the first choice, which not only requires the use of oil-free air compressors, but also the use of chilled water, cooling dryers, or even adsorption dryers in post-treatment systems. However, due to the nature of compressed air and the energy conversion characteristics of the air compressor itself, equipment that uses air compressors and post-treatment systems has high energy consumption and low energy utilization efficiency.

[0003] Refrigerated dryers cannot utilize the waste heat from the air compressor, and the hot compressed air and hot lubricating oil are discharged in the form of thermal energy through an air cooler, which is not environmentally friendly. There are limitations to the working environment of refrigerated dryers. Refrigerated dryers cannot operate properly in environments where the temperature is too low (below 0°C) or too high (above 38°C), ventilation conditions are poor, or air pollution is present, resulting in high power consumption. A 5°C increase in intake air temperature increases power consumption by 35%.

[0004] Adsorption dryers are large in volume and complex in structure, with two adsorbent material tanks and a transport device, resulting in unstable pressure dew points. Issues such as uneven airflow distribution, adsorbent type and filling temperature, and the "tunnel effect" lead to unstable pressure dew points. They also consume high amounts of energy, have poor instantaneous desorption capabilities, require high energy consumption for desorption, and have relatively large pressure losses. Compressed air passes through the adsorbent layer, resulting in large pressure losses and poor compressed air quality. Adsorbent dust is easily mixed into the compressed air, reducing its quality. Summary of the Invention [Problem to be solved by the invention]

[0005] An air compressor compresses air and converts mechanical energy into internal energy. During the air compression process, a large amount of mechanical energy is directly converted into thermal energy, causing the temperature of the compressed air to rise. High compressed air temperatures are unfavorable for the compressor, which is why the discharge pressure of the first-stage compressor is not very high. Furthermore, the hot exhaust gas must be cooled for the second and even third-stage compression. Its temperature is then reduced and it is discharged. The resulting dry compressed air is then sent to the gas-using equipment. The overall system consumes relatively high energy and has poor energy conversion efficiency. High intake air temperatures and humidity can also adversely affect compressor operation. Therefore, pretreatment of the compressor intake air is particularly important. [Means for solving the problem]

[0006] SUMMARY OF THE INVENTION It is an object of the present application to provide an air compressor pre-treatment system that can address the above-mentioned deficiencies of air compressor after-treatment and the waste of heat energy in the air compressor itself.

[0007] The objectives of this application are achieved by using the following technical solutions: The present application relates to an air compressor pretreatment system used for pretreatment of intake air of an air compressor, comprising: a dehumidified air duct arranged upstream of the air compressor and including a dehumidifying unit and a cooling unit, the dehumidifying unit including a dehumidifying wheel including a regeneration zone and a treatment zone; a heat recovery module including a first regeneration air duct having a heat exchanger and the air compressor connected in series on the upstream side and the regeneration zone connected on the downstream side; a conditioned air duct that constitutes a circulating air duct together with the dehumidified air duct; Equipped with When the air compressor operates at a variable frequency, the amount of air in the dehumidified air duct and the conditioned air duct is dynamically balanced.

[0008] In one possible embodiment, the outlet of the dehumidified air duct is provided with a second three-way valve having one end connected to the inlet of the conditioned air duct, and the inlet of the dehumidified air duct is provided with a first three-way valve having one end connected to the outlet of the conditioned air duct.

[0009] In one possible embodiment, when the operating frequency of the air compressor decreases and the intake air volume decreases, the first three-way valve and the second three-way valve are adjusted so that the amount of air entering the conditioned air duct increases and the amount of air in the dehumidified air duct does not change.

[0010] In one possible embodiment, there is one regeneration zone, the regeneration zone is a first regeneration zone, the first regeneration air duct has a first heat coil connected to a group of high-temperature water tanks at its intake end and a group of low-temperature water tanks at its outlet end, and the temperature of the high-temperature water in the group of high-temperature tanks is higher than the temperature of the low-temperature water in the group of low-temperature tanks.

[0011] In one possible embodiment, the group of low-temperature water tanks is arranged upstream of the heat exchanger so that low-temperature water flows into the heat exchanger and undergoes heat exchange within the heat exchanger, and the group of high-temperature water tanks is arranged downstream of the heat exchanger so that the low-temperature water flows into the group of high-temperature water tanks after undergoing heat exchange within the heat exchanger.

[0012] In one possible embodiment, there are two regeneration zones, including a first regeneration zone and a second regeneration zone connected to a second regeneration air duct, the second regeneration air duct being connected at its inlet to the dehumidified air duct and located downstream of the dehumidifying wheel.

[0013] In one possible embodiment, the second regeneration air duct includes a second heat coil connected to a group of high-temperature water tanks at its intake end and a group of low-temperature water tanks at its outlet end, the second heat coil being connected in parallel with the first heat coil.

[0014] In one possible embodiment, as the dehumidifying wheel rotates, it transitions from the first regeneration zone to the second regeneration zone, which has a higher temperature than the first regeneration zone.

[0015] In one possible embodiment, the second regeneration air duct is further provided with an electric heater for further heating the air in the second regeneration air duct heated by the second heating coil.

[0016] In one possible embodiment, the cooling unit comprises a front cooler arranged upstream of the dehumidifying wheel and a rear cooler arranged downstream of the dehumidifying wheel.

[0017] The beneficial effects of the present application include at least the following: The air compressor pretreatment system reduces the intake temperature and humidity of the air compressor, allowing the air compressor's operating section to be changed, reducing operating power and maintenance costs. It also reduces the investment cost and operating energy consumption of the adsorption dryer in the post-treatment equipment, improving the quality and stability of gas quality. By recovering the high-temperature exhaust heat from the air compressor as a regenerative heat input for the pre-treatment equipment and controlling and switching the conditioned air duct of the air compressor pretreatment system, the operating energy consumption of the air compressor pretreatment system is significantly reduced, reducing performance delays of the air compressor pretreatment system caused by changes in air consumption, making the entire system more stable and energy-efficient. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram of an air compression pretreatment system according to a first embodiment of the present application. [Figure 2] FIG. 1 is a schematic diagram of an air compression pretreatment system according to a second embodiment of the present application. [Figure 3] FIG. 10 is a schematic diagram of an air compression pretreatment system according to a third embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, the present application will be described in detail with reference to the accompanying drawings, but the description in this section is for illustrative and explanatory purposes only and should not have any limiting effect on the protection scope of the present application.

[0020] The terms "upstream" and "downstream" are defined by relative positions in the direction of air or water flow, and the terms "high temperature" and "low temperature" refer to relative, not absolute, heights. The orientations or positional relationships indicated by terms such as "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inside," and "outside" are based on those shown in the drawings and are intended solely for the convenience and simplification of the description of this application. They do not imply that the devices or elements referred to have a specific orientation or are constructed or required to operate in a specific direction. Furthermore, the terms "first," "second," and "third" are used solely for descriptive purposes and should not be understood as indicating or implying relative importance.

[0021] 1 to 3, FIG. 1 is a schematic diagram of an air compression pretreatment system according to a first embodiment of the present application, and the present application provides an air compression pretreatment system including a dehumidified air duct 1, a heat recovery module 27, and a conditioned air duct 3.

[0022] The dehumidified air duct 1 is located upstream of the air compressor 5 and dehumidifies and cools the air to be treated before inputting it into the air compressor 5. The dehumidified air duct 1 is equipped with a dehumidification unit 25 and a cooling unit 26. The dehumidification unit 25 is equipped with a dehumidification wheel 19 including a regeneration zone 20 and a treatment zone 21. The air to be treated passes through primary filtration (primary filter 22) to filter out large particle impurities and dust, and then flows into the dehumidified air duct 1 by the force of the fan. As the air passes through the treatment zone 21 of the dehumidification wheel 19, water vapor in the air is adsorbed and dried. After the treatment zone 21 of the dehumidification wheel 19 adsorbs the water vapor, it moves to the regeneration zone 20 and the high-temperature gas desorbs from the regeneration zone 20, thereby causing the dehumidification wheel 19 to operate in a circulating manner. The dehumidified air duct 1 is equipped with a cooling unit 26, which may be a surface cooler or other refrigeration device, and multiple cooling units 26 may be provided. By providing a front cooler 9 upstream of the dehumidifying wheel 19, the low-temperature air to be treated can improve the dehumidification efficiency of the dehumidifying wheel 19. By providing a rear cooler 10 downstream of the dehumidifying wheel 19, the air after dehumidification can be further cooled. The low-temperature, dry air enters the air compressor 5, reducing the energy consumption of the air compressor 5, reducing the maintenance costs of the air compressor 5, and reducing the operating costs of the post-treatment device.

[0023] The heat recovery module 27 has a first regeneration air duct 2, with a heat exchanger 4 and the air compressor 5 connected in series upstream and a regeneration zone 20 connected downstream. The large amount of thermal energy generated when the air compressor 5 is operating is recovered in the heat exchanger 4. As the air passes through the heat exchanger 4, it exchanges heat with the recovered thermal energy, raising the air temperature. The high-temperature air is transported through the first regeneration air duct 2 to the regeneration zone 20 of the dehumidification wheel 19 and regenerated against the dehumidification wheel 19. The regeneration of the high-temperature air utilizes the thermal energy of the air compressor 5, eliminating the need for an additional heating source to heat the air, effectively saving energy and reducing environmental pollution.

[0024] The conditioned air duct 3 and the dehumidified air duct 1 constitute a circulating air duct, and when the air compressor 5 operates at a variable frequency, the amounts of air in the dehumidified air duct 1 and the conditioned air duct 3 are dynamically balanced. A second three-way valve 8 is provided at the outlet of the dehumidified air duct 1, one end of which is connected to the inlet of the conditioned air duct 3. The second three-way valve 8 divides the air flow flowing out of the dehumidified air duct 1 into two flows: one flow that flows into the conditioned air duct 3 and one flow that flows into the downstream air compressor 5. A first three-way valve 7 is provided at the inlet of the dehumidified air duct 1, one end of which is connected to the outlet of the conditioned air duct 3. The first three-way valve 7 controls the air flowing out of the conditioned air duct 3. The air flow is mixed with the air to be treated and flows into the dehumidified air duct 1 via a blower. When the operating frequency of the air compressor 5 increases and the intake air volume increases, the first three-way valve 7 and the second three-way valve 8 are adjusted to reduce the amount of air flowing into the conditioned air duct 3 and increase the amount of air to be treated. Therefore, regardless of changes in the operating frequency of the air compressor 5, the amount of air in the dehumidified air duct 1 remains constant. This eliminates the need to adjust a series of related components, such as the dehumidifying wheel 19 and surface cooler, when the amount of air in the dehumidified air duct 1 changes. These adjustments would increase the system response time and increase instability when the air compressor 5 operates with frequent frequency conversions. Under various operating conditions, even when the operating frequency of the air compressor 5 constantly changes and the intake air volume of the air compressor 5 constantly changes, the air compression pretreatment system can reduce the operating energy consumption of the air compression pretreatment system when the air consumption of the air compressor 5 decreases, and can also reduce performance delays of the air compression pretreatment system when the air consumption of the air compressor 5 increases.

[0025] If there is only one air compressor 5, the thermal energy recovery structure is relatively simple and system stability is ensured, but if multiple air compressors 5 are operating, it is difficult to recover and aggregate the thermal energy of all of the air compressors 5, resulting in poor system stability. Referring to Fig. 2, which is a schematic diagram of an air compression pretreatment system according to a second embodiment of the present application, for the sake of brevity, portions that overlap with the first embodiment will not be described. In the second embodiment, a high-temperature water tank group 28 and a low-temperature water tank group 29 are added, and the first regeneration air duct 2 is equipped with a first heat coil 11 connected to the high-temperature water tank group 28, which includes a high-temperature water tank 13 and a high-temperature water pump 12, at its intake end, and to the low-temperature water tank group 29, which includes a low-temperature water tank 14 and a low-temperature water pump 15, at its outlet end. The high-temperature water in the high-temperature water tank 13 flows into the first heat coil 11 via the high-temperature water pump 12. The incoming air exchanges heat with the high-temperature water through the first heat coil 11, increasing its temperature. The air then flows through the first regeneration air duct 2 into the regeneration zone 20 of the dehumidification wheel 19. The high-temperature water then cools down and flows into the low-temperature water tank 14. The low-temperature water tank group 29 is located upstream of the heat exchanger 4, and the high-temperature water tank group 28 is located downstream of the heat exchanger 4. The low-temperature water in the low-temperature water tank 14 flows into the heat exchanger 4 via the low-temperature water pump 15. The low-temperature water exchanges heat with the high-temperature compressed air from the air compressor 5, increasing its temperature, and then flows back into the high-temperature water tank 13, thus circulating back and forth. The high-temperature water has a higher temperature than the low-temperature water. This embodiment is suitable for an operating environment with, for example, multiple air compressors 5. By recovering the thermal energy from the multiple air compressors 5 as a regeneration heat source for the air compression pretreatment system, the operating energy consumption of the pretreatment system is significantly reduced and the system is highly stable.

[0026] In the second embodiment, the dehumidifying wheel 19 has only one regeneration zone 20. However, referring to FIG. 3, which is a schematic diagram of an air compression pretreatment system according to the third embodiment of the present application, in this embodiment, the dehumidifying wheel 19 has a first regeneration zone 6 and a second regeneration zone 18. That is, the regeneration zone 20 is divided into the first regeneration zone 6 and the second regeneration zone 18. The heat recovery module 27 has a second regeneration air duct 23. The second regeneration air duct 23 is connected at its inlet to the dehumidified air duct 1. The dehumidifying wheel 19 is located downstream of the dehumidifying wheel 19, and a valve 24 is provided at the inlet of the second regeneration air duct 23 to control the amount of air flowing into the second regeneration air duct 23. The moisture in the air flowing out of the treatment zone 21 of the dehumidifying wheel 19 is adsorbed by the dehumidifying wheel 19, causing the temperature to rise and the humidity to decrease, resulting in dry air. A portion of the treated air flows into the after-cooler 10, where it is cooled and then flows into the air compressor 5, and the remaining portion flows into the second regeneration air duct 23. As the dehumidifying wheel 19 rotates, the air moves from the first regeneration zone 6 to the second regeneration zone 18, and the temperature of the second regeneration zone 18 is higher than that of the first regeneration zone 6.

[0027] The second regeneration air duct 23 is provided with a second heat coil 16 for heating the air in the second regeneration air duct 23. The heated air flows into the second regeneration zone 18. The second heat coil 16 has an intake end connected to a group of high-temperature water tanks 28 and an outlet end connected to a group of low-temperature water tanks 29. The second heat coil 16 is connected in parallel with the first heat coil 11, allowing the high-temperature water in the high-temperature water tank 13 to be supplied simultaneously to the first heat coil 11 and the second heat coil 16. The low-temperature water after heat exchange in both the first heat coil 11 and the second heat coil 16 is collected in the low-temperature water tank 14, and the recovered thermal energy of the air compressor 5 can be supplied to multiple regeneration air ducts. This further improves the dehumidification effect of the dehumidifying wheel 19, improves the treatment efficiency of the air compression pretreatment system, and reduces the operating energy consumption of the air compression pretreatment system. To ensure a stable regeneration temperature in the second regeneration air duct 23, an electric heater 17 is provided in the second regeneration air duct 23 to further heat the air in the second regeneration air duct 23. In this embodiment, the dehumidifying wheel 19 has a first regeneration zone 6 and a second regeneration zone 18, and the first regeneration zone 6 and the second regeneration zone 18 are each provided with a regeneration air duct that recovers thermal energy from different angles, improving the regeneration effect of the regeneration zone 20 of the dehumidifying wheel 19 and fully recovering thermal energy, improving energy utilization, and reducing operating energy consumption of the pretreatment equipment. The configuration of the second regeneration air duct 23 in this embodiment can also be applied to embodiment 1.

[0028] Related technologies use cooling dryers and adsorption dryers for post-treatment, but cooling dryers consume high power, increasing power consumption by 35% for every 5°C increase in inlet air temperature, and the adsorbent in adsorption dryers has poor instantaneous desorption capability, requiring high energy consumption for desorption.The air compression pre-treatment system starts with pre-treatment, adjusting the temperature and humidity of the air entering the air compressor 5 and ensuring the temperature and humidity of the air output from the air compressor 5, thereby fundamentally resolving the pressure dew point and energy consumption issues of the cooling dryer and adsorption dryer when the air discharged from the air compressor 5 enters post-treatment.

[0029] The above-described embodiments of the present application do not limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included within the scope of protection of the claims of the present application. [Explanation of symbols]

[0030] 1, Dehumidifying air duct, 2. The first regenerative air duct; 3, regulated air duct, 4, heat exchanger, 5. Air compressor, 6. First Play Zone, 7. The first three-way valve, 8. The second three-way valve, 9, front cooler, 10, rear cooler, 11, the first heating coil, 12. High temperature water pump, 13. High temperature water tank, 14. Low temperature water tank, 15. Low temperature water pump, 16, the second heating coil, 17. Electric heater, 18, second regeneration zone, 19. Dehumidifying wheel, 20, Regeneration Zone, 21, treatment zone, 22, primary filter, 23, the second regeneration air duct, 24, valve, 25. Dehumidification unit, 26. Cooling unit, 27, heat recovery module, 28. High-temperature water tank group 29. Low temperature water tank group

Claims

1. An air compressor pretreatment system used for pretreatment of intake air of an air compressor, comprising: a dehumidified air duct arranged upstream of the air compressor and including a dehumidifying unit and a cooling unit, the dehumidifying unit including a dehumidifying wheel including a regeneration zone and a treatment zone; a heat recovery module including a first regeneration air duct having a heat exchanger and the air compressor connected in series on the upstream side and the regeneration zone connected on the downstream side; a conditioned air duct that constitutes a circulating air duct together with the dehumidified air duct; Equipped with the amount of air in the dehumidified air duct and the conditioned air duct is dynamically balanced when the air compressor operates at a variable frequency; Air compression pretreatment system.

2. a second three-way valve having one end connected to the inlet of the conditioned air duct is provided at the outlet of the dehumidified air duct, and a first three-way valve having one end connected to the outlet of the conditioned air duct is provided at the inlet of the dehumidified air duct; 10. The air compression pretreatment system of claim 1.

3. adjusting the first three-way valve and the second three-way valve so that when the operating frequency of the air compressor drops and the intake air volume decreases, the amount of air entering the regulated air duct increases and the amount of air entering the dehumidified air duct does not change; 3. The air compression pretreatment system of claim 2.

4. The regeneration zone is one, and the regeneration zone is a first regeneration zone, and the first regeneration air duct is equipped with a first heat coil having a water intake end connected to a high-temperature water tank group and a water outlet end connected to a low-temperature water tank group, and the temperature of the high-temperature water in the high-temperature tank group is higher than the temperature of the low-temperature water in the low-temperature tank group.

4. The air compression pretreatment system of claim 3.

5. The low-temperature water tank group is disposed upstream of the heat exchanger so that low-temperature water flows into the heat exchanger and undergoes heat exchange therein, and the high-temperature water tank group is disposed downstream of the heat exchanger so that the low-temperature water flows into the high-temperature water tank group after undergoing heat exchange therein.

5. The air compression pretreatment system of claim 4.

6. The regeneration zone is two, including a first regeneration zone and a second regeneration zone connected to a second regeneration air duct, the second regeneration air duct being connected at its inlet to the dehumidified air duct and being located downstream of the dehumidifying wheel.

6. The air compression pretreatment system of claim 5.

7. The second regeneration air duct includes a second heat coil having a water intake end connected to a high-temperature water tank group and a water outlet end connected to a low-temperature water tank group, and the second heat coil is connected in parallel with the first heat coil.

7. The air compression pretreatment system of claim 6.

8. When the dehumidifying wheel rotates, the dehumidifying wheel moves from the first regeneration zone to the second regeneration zone, the second regeneration zone having a temperature higher than that of the first regeneration zone.

7. The air compression pretreatment system of claim 6.

9. The second regeneration air duct is further provided with an electric heater that further heats the air in the second regeneration air duct that has been heated by the second heat coil.

8. The air compression pretreatment system of claim 7.

10. The cooling unit includes a front cooler disposed upstream of the dehumidifying wheel and a rear cooler disposed downstream of the dehumidifying wheel.

10. The air compression pretreatment system of claim 1.

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