Ultra-low water vapor partial pressure regeneration dryer system and its control method

Abstract

The present invention provides an ultra-low water vapor partial pressure regeneration dryer system and its control method. The system includes an air inlet, an air outlet, first and second adsorption towers used alternately, a heater, a deep drying component, and supporting pipelines, valves, and a control system. The towers and the deep drying component are filled with adsorption packing, and adsorption and regeneration are achieved through a specific connection flow path. Some systems are also equipped with a blower and a heat exchanger. The control method stipulates the working cycle steps of the adsorption towers according to different system configurations. The invention can effectively reduce the water vapor partial pressure of the regeneration gas, achieve efficient drying through optimized flow path design and working methods, and can accurately control each link through the control system to meet the requirements of application scenarios with high requirements for gas drying degree, and has advantages such as low energy consumption and good drying effect.

Description

Technical Field

[0001] The present invention relates to the technical field of regenerative dryers, and in particular to an ultra-low water vapor partial pressure regenerative dryer system and its control method. Background Art

[0002] In industrial production, many processes have extremely high requirements for the dryness of compressed gas. Therefore, adsorption dryers have become widely used drying equipment. Its core working principle is based on the adsorption of moisture in compressed gas by adsorbents, thereby achieving the purpose of gas drying. In a common twin-tower adsorption dryer, through the alternating operation of two adsorption towers, when one tower is performing adsorption operation, the other tower is regenerating the adsorbent, so as to ensure the continuous supply of dry compressed gas.

[0003] During the operation of an adsorption dryer, the regeneration effect of the adsorbent plays a decisive role in the overall performance of the dryer. The regeneration process mainly involves passing hot air through the adsorbent to evaporate and desorb the adsorbed moisture in the adsorbent, thereby restoring its adsorption capacity. Research shows that the water vapor partial pressure and regeneration temperature of the regeneration gas are the key factors affecting the residual adsorption amount of the adsorbent during regeneration. Specifically, the lower the water vapor partial pressure of the regeneration gas or the higher the regeneration temperature, the more thorough the desorption of the adsorbent, and the dryer can achieve a better drying effect, providing higher-quality dry compressed gas for industrial production.

[0004] However, currently, in order to reduce the residual adsorption amount of the adsorbent during regeneration in existing adsorption dryers, most methods adopt the way of increasing the regeneration temperature. Although this method can improve the drying effect to a certain extent, it brings serious energy consumption problems. Increasing the regeneration temperature requires consuming a large amount of external heat energy or electrical energy to heat up the regeneration gas. This not only greatly increases the production cost of enterprises, but also causes greater pressure on energy supply and the environment. Especially in the current context of advocating energy conservation and emission reduction, this high-energy-consuming drying method is increasingly difficult to meet the requirements of sustainable development.

[0005] To solve the above problems, those skilled in the art have been seeking more efficient and energy-saving technical solutions for adsorption dryers. Some attempts focus on developing new adsorbents, but the research and development cycle of new adsorbents is long, the cost is high, and there may be compatibility problems in actual applications; others focus on optimizing the equipment structure, but existing optimization schemes can only reduce energy consumption to a limited extent and cannot fundamentally solve the problem of high energy consumption.

[0006] Therefore, developing a dryer system that can effectively reduce the residual adsorption of adsorbent regeneration without significantly increasing energy consumption or adjusting the regeneration temperature, and can stably output low dew point compressed gas, has become an important issue to be solved in the field of adsorption dryers. The ultra-low water vapor partial pressure regeneration dryer system and its control method proposed in the present invention are born in response to this background, aiming to fill the gap in the prior art and provide a more energy-saving and efficient drying solution for industrial production. Summary of the invention

[0007] The embodiments of the present invention provide an ultra-low water vapor partial pressure regeneration dryer system and a control method thereof, which aims to address the problems that existing adsorption dryers in the current technology mostly reduce the residual adsorption amount of adsorbent regeneration by increasing the regeneration temperature, resulting in a significant increase in system energy consumption, and there is currently no technical solution to effectively solve the high energy consumption problem.

[0008] The core technology of the present invention is to regenerate the filler in the adsorption tower under ultra-low water vapor partial pressure by secondary deep drying of part of the finished gas at the system outlet as regeneration gas, and optimize the system structure and process at the same time to achieve the purpose of reducing the residual adsorption amount of adsorbent regeneration, stably outputting low dew point compressed gas and saving energy.

[0009] In a first aspect, the present invention provides an ultra-low water vapor partial pressure regeneration dryer system, the system comprising:

[0010] Inlet and exhaust ports for the entry and exit of gas;

[0011] The first adsorption tower and the second adsorption tower are used cyclically and switched, and both are filled with fillers with moisture adsorption capacity;

[0012] A heater, used for heating the gas;

[0013] Deep drying components are filled with fillers with moisture adsorption capabilities;

[0014] Supporting pipelines, valves and control systems;

[0015] Among them, there are also the following connecting flow paths:

[0016] The air inlet, the first adsorption tower, and the exhaust port are sequentially connected to form an adsorption flow path 1;

[0017] The air inlet, the second adsorption tower, and the exhaust port are sequentially connected to form an adsorption flow path 2;

[0018] The exhaust port, the deep drying component, the heater, and the first adsorption tower are sequentially connected to form a heating regeneration flow path 1;

[0019] The exhaust port, the deep drying component, the heater, and the second adsorption tower are sequentially connected to form a second heating regeneration flow path;

[0020] The exhaust port, the heater, and the deep drying component are connected in sequence to form the third heating regeneration flow path.

[0021] Furthermore, it also includes a blower and a shell-and-tube heat exchanger. A vacuum exhaust port is provided on the air outlet side of the blower. The blower, any one of the adsorption towers, and the high-temperature side of the heat exchanger form a circulating cold blow cooling flow path.

[0022] Furthermore, the maximum vacuum degree of the blower is not lower than 30 kPa.

[0023] Furthermore, the low-temperature side of the heat exchanger is connected in series in the exhaust main pipe of the deep drying component, and the cold and hot media flow in opposite directions in the heat exchanger.

[0024] Furthermore, the packing inside the first adsorption tower and the second adsorption tower is one or more of activated alumina, silica gel, silica-alumina gel, or molecular sieve, and the packing inside the deep drying component is molecular sieve.

[0025] Furthermore, the packing weights of the first adsorption tower and the second adsorption tower are the same, and the packing weight of the deep drying component is 20 - 35% of the single-tower packing weight of the first adsorption tower or the second adsorption tower.

[0026] Furthermore, a self-operated flow regulating valve is provided at the exhaust port.

[0027] In the second aspect, the present invention provides a control method for an ultra-low water vapor partial pressure regeneration dryer system. The working cycle of any one of the adsorption towers includes the following steps:

[0028] Step S1: Adsorb the moisture in the compressed gas by using the characteristics of the packing inside the tower;

[0029] Step S2: Release the pressure inside the tower to make it the same as the ambient atmospheric pressure;

[0030] Step S3: Allow a preset amount of finished gas to be further dehydrated by the deep drying component, then enter the adsorption tower after being heated by the heater, regenerate the packing inside the tower, and then discharge from the tower body;

[0031] Step S4: Let a preset amount of finished gas enter the adsorption tower to carry out the heat of the packing inside the tower;

[0032] Step S5: Let a preset amount of finished gas enter the adsorption tower to gradually increase the pressure inside the tower to be the same as that of the other tower;

[0033] Step S6: The adsorption tower waits to enter the next adsorption cycle, and at the same time, let a preset amount of finished gas be heated by the heater to carry out heat regeneration treatment on the packing inside the deep drying component.

[0034] In the third aspect, the present invention provides a control method for an ultra-low water vapor partial pressure regeneration dryer system. The working cycle of any one of the adsorption towers includes the following steps:

[0035] Step S1: Adsorb the moisture in the compressed gas by utilizing the characteristics of the packing in the tower.

[0036] Step S2: Release the pressure inside the tower to make it the same as the ambient atmospheric pressure.

[0037] Step S3: Let a preset amount of finished gas pass through the deep drying component to further remove moisture, then enter the adsorption tower after being heated by the heater, regenerate the packing in the tower, and then be discharged from the tower body.

[0038] Step S4: Use a blower to extract the gas inside the tower. After the pressure inside the tower drops to -20 kPa(g), powered by the blower, make the gas inside the tower circulate and exchange heat with the low-temperature medium in the heat exchanger to gradually reduce the temperature of the packing in the tower.

[0039] Step S5: Let a preset amount of finished gas enter the adsorption tower to further reduce the temperature of the packing in the tower.

[0040] Step S6: Let a preset amount of finished gas enter the adsorption tower to gradually increase the pressure inside the tower to be the same as that of another tower.

[0041] Step S7: The adsorption tower waits to enter the next adsorption cycle. Meanwhile, let a preset amount of finished gas be heated by the heater to perform heat regeneration treatment on the packing in the deep drying component.

[0042] Further, during the cycle cooling process, when the temperature difference between the outlet temperature of the high-temperature medium and the inlet temperature of the low-temperature medium in the heat exchanger is not higher than the first preset temperature, stop the cycle cooling and enter the next stage; if when stopping the cycle cooling, the temperature difference between the temperature inside the adsorption tower and the temperature at the system exhaust port is not higher than the second preset temperature, then step S5 is no longer executed.

[0043] The main contributions and innovations of the present invention are as follows:

[0044] 1. High-efficiency drying: By setting adsorption towers and deep drying components with cyclic switching, and filling appropriate adsorption packing in each tower and component, the regeneration gas is deeply dried, which is significantly different from the existing multi-stage drying treatment, effectively reducing the water vapor partial pressure of the gas and meeting the application scenarios with high requirements for the gas drying degree.

[0045] 2. Energy conservation and consumption reduction: The system is provided with a heat exchanger and a blower, which can recycle heat. Through the reverse flow heat exchange of hot and cold media, efficient cycle cooling and blowing for temperature reduction can be achieved, reducing energy loss.

[0046] 3. Process optimization: Clear and reasonable working cycle steps of the adsorption tower, such as adsorption, pressure release, regeneration, cooling, etc., are carried out in an orderly manner, ensuring the continuous and stable operation of the system and improving the drying efficiency.

[0047] 4. Precise control: The equipped control system can precisely manipulate and monitor the operating status of valves, equipment, etc., adjust various parameters according to system requirements, and ensure that the system always operates under the best working conditions.

[0048] Details of one or more embodiments of the present invention are set forth in the following drawings and description to make other features, objects, and advantages of the present invention more concise and understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings described herein are used to provide a further understanding of the present invention and form a part of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0050] Figure 1 is a structural diagram of an ultra-low water vapor partial pressure regeneration dryer system according to an embodiment of the present invention;

[0051] Figure 2 is a structural diagram of an ultra-low water vapor partial pressure regeneration dryer system configured with a blower according to an embodiment of the present invention.

[0052] In the figure, 1, air inlet; 2, exhaust port; T1, first adsorption tower; T2, second adsorption tower; T3, deep drying component; HR, heat exchanger; RB, blower; MF1, deep drying component exhaust silencer; MF2, T1 tower exhaust silencer; MF3, T2 tower exhaust silencer; V1, heating and cold blowing switching valve; V2, heating regeneration inlet valve; V3, deep drying flow regulating valve; V4, T2 tower finished gas exhaust valve; V5, T1 tower finished gas exhaust valve; V6, regeneration gas flow regulating valve; V7, T1 tower heating regeneration inlet valve; V8, T2 tower heating regeneration inlet valve; V9, circulating cooling main valve; V10, T1 tower regeneration gas exhaust valve; V11, T1 tower circulating cooling valve; V12, T2 tower circulating cooling valve; V13, T2 tower regeneration gas exhaust valve; V14, T1 tower adsorption inlet valve; V15, T2 tower adsorption inlet valve; V16, vacuum exhaust valve; V17, exhaust flow regulating valve; EH, heater. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with one or more embodiments of this specification. On the contrary, they are merely examples of devices and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0054] It should be noted that: In other embodiments, the steps of the corresponding methods are not necessarily executed in the order shown and described in this specification. In some other embodiments, the steps included in the method may be more or less than those described in this specification. In addition, a single step described in this specification may be decomposed into multiple steps for description in other embodiments; and multiple steps described in this specification may also be combined into a single step for description in other embodiments.

[0055] Most existing adsorption dryers reduce the residual adsorbed amount of the adsorbent by increasing the regeneration temperature, resulting in a significant increase in system energy consumption, and there is currently no effective technical solution to solve this high energy consumption problem.

[0056] Based on this, the present invention is based on a new technical solution to solve the problems existing in the prior art.

[0057] Embodiment 1

[0058] The present invention aims to propose an ultra-low water vapor partial pressure regeneration dryer system. Specifically, referring to Figure 1 , the system includes:

[0059] An air inlet 1 and an exhaust outlet 2 for the inlet and outlet of gas;

[0060] A first adsorption tower T1 and a second adsorption tower T2, which are used cyclically and alternately, and both are filled with fillers having the ability to adsorb moisture;

[0061] A heater EH for heating the gas;

[0062] A deep drying component T3 filled with fillers having the ability to adsorb moisture;

[0063] Supporting pipelines, valves and control systems;

[0064] Among them, there are also the following connected flow paths:

[0065] The air inlet 1, the first adsorption tower T1, and the exhaust outlet 2 are sequentially connected to form an adsorption flow path 1;

[0066] The air inlet 1, the second adsorption tower T2, and the exhaust outlet 2 are sequentially connected to form an adsorption flow path 2;

[0067] The exhaust outlet 2, the deep drying component T3, the heater EH, and the first adsorption tower T1 are sequentially connected to form a heating regeneration flow path 1;

[0068] The exhaust outlet 2, the deep drying component T3, the heater EH, and the second adsorption tower T2 are sequentially connected to form a heating regeneration flow path 2;

[0069] The exhaust outlet 2, the heater EH, and the deep drying component T3 are sequentially connected to form a heating regeneration flow path 3.

[0070] In this embodiment, the packing inside the first adsorption tower T1 and the second adsorption tower T2 is one or more of activated alumina, silica gel, silica-alumina gel or molecular sieve, and the packing inside the deep drying assembly T3 is molecular sieve. Preferably, the weights of the packing in the first adsorption tower T1 and the second adsorption tower T2 are the same, and the weight of the packing in the deep drying assembly T3 is 20-35% of the weight of the packing in a single tower of the first adsorption tower T1 or the second adsorption tower T2 (because if there is too much packing in the deep drying assembly, a large amount of energy will be consumed during its regeneration process; if there is too little packing, it will be difficult to achieve the purpose of further reducing the moisture content of the regeneration gas).

[0071] Specifically, molecular sieve is an excellent adsorbent. It has a larger specific surface area than alumina, and its surface pore size is very uniform, with good adsorption selectivity. Even when the water vapor partial pressure is very low, it still has a large adsorption capacity (activated alumina and silica gel only have a large adsorption capacity at high partial pressures). Therefore, molecular sieve is suitable for deep dehydration drying of compressed air. Using molecular sieve as the packing in the deep drying assembly can further dehydrate and dry the compressed gas adsorbed by the adsorption tower.

[0072] Preferably, as Figure 2 shown, the system further includes a blower RB and a shell-and-tube heat exchanger HR. A vacuum exhaust port V16 is provided on the air outlet side of the blower RB. The blower RB, any one of the adsorption towers and the high-temperature side of the heat exchanger HR form a circulating cold blow cooling flow path; the low-temperature side of the heat exchanger HR is connected in series in the exhaust main pipe of the deep drying assembly T3, and the cold and hot media flow in opposite directions in the heat exchanger HR. The maximum vacuum degree of the blower RB is not less than 30 kPa. Figure 2 In Figure 1 on the basis of adding a blower and a heat exchanger, a circulating cooling process is added to the process, and Figure 2 the solution of

[0073] using circulating cooling to replace most (or all) of the finished gas cold blow process can achieve the purpose of reducing gas consumption and saving energy.

[0074] Among them, the self-acting flow regulating valve 17 automatically changes the resistance coefficient according to the changes in the system operating conditions. Within a certain pressure difference range, it can effectively control the passing flow rate to maintain a constant value. That is, when the pressure difference before and after the valve increases, the valve automatically closes slightly to keep the flow rate from increasing. Conversely, when the pressure difference decreases, the valve automatically opens wider, and the flow rate still remains constant. By installing a self-acting flow regulating valve at the exhaust port of the ultra-low water vapor partial pressure regeneration dryer system, the system load can be stabilized within the design operating conditions. In addition, when multiple ultra-low water vapor partial pressure regeneration dryer systems are jointly applied to the header system, the self-acting flow regulating valve can also play a role in evenly distributing the flow rate.

[0075] To facilitate the understanding of the system solution, Table 1 is used for explanation:

[0076] Table 1 Operating Process Flow and Valve Status Table

[0077]

[0078] When the first adsorption tower T1 or the second adsorption tower T2 of this system in Table 1 is in the adsorption state, the other tower sequentially completes several working steps such as pressure relief, heating regeneration, circulating cooling, finished gas cold blow, pressure boost, and standby.

[0079] Specifically, for each stage of the adsorption-regeneration process of any tower (taking the adsorption of the second adsorption tower T2 as an example):

[0080] 1. The second adsorption tower T2 adsorbs. Adsorption process: The wet compressed gas enters from the air inlet 1, passes through the T2 tower adsorption inlet valve V15 and enters the second adsorption tower T2. The moisture in the wet compressed gas is adsorbed by the packing in the tower, and the dried compressed gas passes through the T2 tower finished gas exhaust valve V4 and enters the downstream gas-using unit from the exhaust port 2.

[0081] 2. The second adsorption tower T2 relieves pressure. The compressed gas in the first adsorption tower T2 passes through the T2 tower regeneration gas exhaust valve V13 and is discharged through the T2 tower exhaust silencer MF3.

[0082] 3. The second adsorption tower T2 is heated and regenerated. A small amount of finished gas from the system exhaust main pipe is used as the regeneration gas and enters the deep drying component through the heating regeneration inlet valve V2. The moisture in the regeneration gas is further adsorbed by the packing in the deep drying component and then enters the heater. After being heated by the heater, the high-temperature regeneration gas sequentially passes through the heating and cold blow switching valve V1, the regeneration gas flow regulating valve V6, and the T2 tower heating regeneration inlet valve V8, enters the second adsorption tower T2, heats up the packing in the tower, and entrains the moisture separated from the packing and is discharged through the T2 tower regeneration gas exhaust valve V13 and the T2 tower exhaust silencer MF3.

[0083] 4. Circulating cooling of the second adsorption tower T2. The blower extracts the gas in the second adsorption tower T2, heat exchanger HR and the circulating cooling pipeline, and discharges it through the vacuum exhaust valve V16 until the pressure in the second adsorption tower T2 drops below -20 kPa(g). After the pressure reduction is completed, close the vacuum exhaust valve V16, and the blower continuously transports low-pressure gas to circulate through the heat exchanger HR to exchange heat with the low-temperature fluid, gradually reducing the temperature of the packing in the second adsorption tower T2.

[0084] 5. Cold blowing of the finished gas in the second adsorption tower T2. A small amount of finished gas from the system exhaust main pipe is used as the cold blowing gas and sequentially passes through the heating and cold blowing switching valve V1, the regenerated gas flow regulating valve V6, and the T2 tower heating and regeneration inlet valve V8, enters the second adsorption tower T2, cools down the packing in the tower, and is discharged through the T2 tower regenerated gas exhaust valve V13 and the T2 tower exhaust silencer MF3.

[0085] 6. Pressurization of the second adsorption tower T2. A small amount of finished gas from the system exhaust main pipe is used as the cold blowing gas and sequentially passes through the heating and cold blowing switching valve V1, the regenerated gas flow regulating valve V6, and the T2 tower heating and regeneration inlet valve V8, enters the second adsorption tower T2, and the pressure in the tower gradually increases.

[0086] 7. Standby of the second adsorption tower T2. The second adsorption tower T2 maintains the working pressure and is ready to enter the next adsorption stage.

[0087] The following table shows the more specific operating process flow and valve status of this system:

[0088]

[0089] Among them, the working principle of the blower RB in this system is to increase the pressure of air or gas through rotor movement and volume change. The blower inhales gas through the inlet valve, and the rotor rotates to push the air or gas from the low-pressure end to the high-pressure end. The blower can both inhale and blow, depending on its design and application scenarios.

[0090] Different types of blowers have different gas flow characteristics and pressure performances, and the negative pressure levels at their inlets will also vary. The wind pressure of a single-stage centrifugal fan is usually between 3 - 10 kPa and is suitable for general gas transportation and ventilation scenarios. While the wind pressure of a two-stage centrifugal fan is higher, reaching 20 - 45 kPa; the wind pressure of a high-pressure blower is usually between 15 - 70 kPa.

[0091] The heat exchanger HR of this system is connected in series in the main exhaust pipe of the dryer. By using the finished gas to participate in the circulation cooling process, the system can operate without the need to externally provide low-temperature fluid. This not only improves the system integration but also reduces the overall operating energy consumption. After the finished gas flows out from the first adsorption tower T1 through the valve V5 and from the second adsorption tower T2 through the valve V4, the subsequent part of the pipeline leading to the exhaust port 2 can be regarded as the main exhaust pipe of the dryer. Its function is to collect the dried gas and transport it to the exhaust port for discharging from the system. At the same time, the low-temperature side of the heat exchanger HR is connected in series here and is used for heat exchange with the high-temperature gas in the circulation cold-blowing temperature reduction flow path.

[0092] The countercurrent heat transfer of this heat exchanger HR means that the hot and cold fluids exchange heat in the heat exchanger in opposite flow directions. In countercurrent heat transfer, the temperature difference between the hot and cold fluids is the largest, so the maximum heat exchange effect can be achieved. At the same time, countercurrent heat transfer can avoid the problem of insufficient heat exchange caused by too low or too high temperature crossover points.

[0093] Embodiment 2

[0094] Based on the same concept, the present invention also proposes a control method for an ultra-low water vapor partial pressure regeneration dryer system. The working cycle of any adsorption tower includes the following steps:

[0095] Step S1: Adsorb the moisture in the compressed gas by utilizing the characteristics of the packing in the tower;

[0096] Step S2: Release the pressure in the tower to make it the same as the ambient atmospheric pressure;

[0097] Step S3: Let a preset amount of finished gas be further dehydrated by the deep drying component T3, then enter the adsorption tower after being heated by the heater EH, regenerate the packing in the tower, and then discharge from the tower body;

[0098] Step S4: Let a preset amount of finished gas enter the adsorption tower to carry out the heat of the packing in the tower;

[0099] Step S5: Let a preset amount of finished gas enter the adsorption tower to gradually increase the pressure in the tower to the same as that of the other tower;

[0100] Step S6: The adsorption tower waits to enter the next adsorption cycle. At the same time, let a preset amount of finished gas be heated by the heater EH to carry out heat regeneration treatment on the packing in the deep drying component T3.

[0101] Embodiment 3

[0102] Based on the same concept, the present invention also proposes a control method for an ultra-low water vapor partial pressure regeneration dryer system. The working cycle of any adsorption tower includes the following steps:

[0103] Step S1: Adsorb the moisture in the compressed gas by utilizing the characteristics of the packing in the tower;

[0104] Step S2: Release the pressure inside the tower to make it the same as the ambient atmospheric pressure;

[0105] Step S3: Let a preset amount of finished gas pass through the deep drying component T3 to further remove moisture, then enter the adsorption tower after being heated by the heater EH, regenerate the packing inside the tower, and then be discharged from the tower body;

[0106] Step S4: Use the blower RB to extract the gas inside the tower. After the pressure inside the tower drops to -20 kPa(g), powered by the blower RB, make the gas inside the tower circulate and exchange heat with the low-temperature medium in the heat exchanger HR to gradually reduce the temperature of the packing inside the tower;

[0107] Step S5: Let a preset amount of finished gas enter the adsorption tower to further reduce the temperature of the packing inside the tower; the purpose of this step is to directly reduce the temperature of the packing inside the tower by using the finished gas. However, if the temperature inside the tower is not significantly higher than the temperature of the gas at the system exhaust port at the end of the cyclic cold blow, there is no need to perform the finished gas cold blow again, that is, step S5 is no longer executed.

[0108] Step S6: Let a preset amount of finished gas enter the adsorption tower to gradually increase the pressure inside the tower to be the same as that of the other tower;

[0109] Step S7: The adsorption tower waits to enter the next adsorption cycle. At the same time, let a preset amount of finished gas be heated by the heater EH to perform a heating regeneration treatment on the packing inside the deep drying component T3.

[0110] In this embodiment, during the cyclic cooling process, when the temperature difference between the outlet temperature of the high-temperature medium and the inlet temperature of the low-temperature medium in the heat exchanger HR is not higher than 5°C, stop the cyclic cooling and enter the next stage; if the temperature difference between the temperature inside the adsorption tower and the temperature at the system exhaust port 2 is not higher than 3°C when stopping the cyclic cooling, then step S5 is no longer executed.

[0111] Preferably, the cyclic cooling time can be set to a fixed value or can be automatically controlled according to the actual operating state of the system. In the case of automatic control, preferably use the temperature of the packing inside the tower as a reference value. For example, stop the cyclic cooling when the temperature difference between the outlet temperature of the high-temperature medium and the inlet temperature of the low-temperature medium in the heat exchanger is not higher than 5°C. (If the selected difference is too high, the cooling target cannot be actually achieved; if the selected difference is too low, it will affect the economic efficiency of the system operation).

[0112] Those skilled in the art should understand that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity in description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as falling within the scope described in this specification.

[0113] The above embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the appended claims.

Claims

1. Ultra-low water vapor partial pressure regeneration dryer system, characterized in that: include: An air inlet (1) and an air outlet (2) for the inlet and outlet of gas; The first adsorption tower (T1) and the second adsorption tower (T2) are used in a cyclic switching manner, and are both filled with fillers having water adsorption capacity; A heater (EH), used to heat the gas; Deep drying component (T3), which is filled with fillers with moisture adsorption capacity; Supporting pipelines, valves and control systems; The fillers inside the first adsorption tower (T1) and the second adsorption tower (T2) are one or more of activated alumina, silica gel, silica-alumina gel or molecular sieve, and the filler inside the deep drying component (T3) is molecular sieve; Among them, there are also the following connecting flow paths: The air inlet (1), the first adsorption tower (T1), and the exhaust port (2) are connected in sequence to form an adsorption flow path 1; The air inlet (1), the second adsorption tower (T2), and the exhaust port (2) are connected in sequence to form an adsorption flow path 2; The exhaust port (2), the deep drying component (T3), the heater (EH), and the first adsorption tower (T1) are connected in sequence to form a heating regeneration flow path 1; The exhaust port (2), the deep drying component (T3), the heater (EH), and the second adsorption tower (T2) are connected in sequence to form a second heating regeneration flow path; The exhaust port (2), the heater (EH), and the deep drying component (T3) are connected in sequence to form a heating regeneration flow path three.

2. The ultra-low water vapor partial pressure regeneration dryer system according to claim 1, characterized in that: It also includes a blower (RB) and a partition heat exchanger (HR), wherein the air outlet side of the blower (RB) is provided with a vacuum exhaust port (V16), and the blower (RB), any adsorption tower and the high-temperature side of the heat exchanger (HR) form a circulating cold-blowing cooling flow path.

3. The ultra-low water vapor partial pressure regeneration dryer system according to claim 2, characterized in that: The maximum vacuum degree of the blower (RB) is not less than 30 kPa.

4. The ultra-low water vapor partial pressure regeneration dryer system according to claim 2, characterized in that: The low temperature side of the heat exchanger (HR) is connected in series to the exhaust main pipe of the deep drying component (T3), and the cold and hot media flow in the heat exchanger (HR) in reverse directions.

5. The ultra-low water vapor partial pressure regeneration dryer system according to claim 1, characterized in that: The packing weights of the first adsorption tower (T1) and the second adsorption tower (T2) are the same, and the packing weight of the deep drying component (T3) is 20-35% of the packing weight of the first adsorption tower (T1) or the second adsorption tower (T2).

6. The ultra-low water vapor partial pressure regeneration dryer system according to any one of claims 1 to 5, characterized in that: A self-operated flow regulating valve (V17) is provided at the exhaust port (2).

7. The control method of the ultra-low water vapor partial pressure regeneration dryer system according to any one of claims 1 or 5-6, characterized in that: The working cycle of any adsorption tower includes the following steps: Step S1: utilizing the characteristics of the packing in the tower to adsorb the moisture in the compressed gas; Step S2: releasing the pressure in the tower to make it the same as the ambient atmospheric pressure; Step S3: a preset amount of finished gas is further dehydrated by a deep drying component (T3), and then heated by a heater (EH) before entering an adsorption tower, where the packing in the tower is regenerated and then discharged from the tower body; Step S4: allowing a preset amount of finished gas to enter the adsorption tower to remove heat from the packing in the tower; Step S5: allowing a preset amount of finished gas to enter the adsorption tower, and gradually increasing the pressure in the tower to the same as that of the other tower; Step S6: The adsorption tower waits to enter the next adsorption cycle, and at the same time, a preset amount of finished gas is heated by the heater (EH) to heat and regenerate the filler in the deep drying component (T3).

8. The control method of the ultra-low water vapor partial pressure regeneration dryer system according to any one of claims 2 to 4, characterized in that: The working cycle of any adsorption tower includes the following steps: Step S1: utilizing the characteristics of the packing in the tower to adsorb the moisture in the compressed gas; Step S2: releasing the pressure in the tower to make it the same as the ambient atmospheric pressure; Step S3: a preset amount of finished gas is further dehydrated by a deep drying component (T3), and then heated by a heater (EH) before entering an adsorption tower to regenerate the packing in the tower before being discharged from the tower body; Step S4: extracting the gas in the tower by using a blower (RB) to reduce the pressure in the tower to -20 kPa (g), and then the blower (RB) provides power to circulate heat exchange between the gas in the tower and the low-temperature medium in the heat exchanger (HR), thereby gradually reducing the temperature of the packing in the tower; Step S5: allowing a preset amount of finished gas to enter the adsorption tower to further reduce the packing temperature in the tower; Step S6: allowing a preset amount of finished gas to enter the adsorption tower, and gradually increasing the pressure in the tower to the same as that of the other tower; Step S7: The adsorption tower waits to enter the next adsorption cycle, and at the same time, a preset amount of finished gas is heated by the heater (EH) to heat and regenerate the filler in the deep drying component (T3).

9. The control method according to claim 8, characterized in that: During the circulating cooling process, when the difference between the outlet temperature of the high-temperature medium in the heat exchanger (HR) and the inlet temperature of the low-temperature medium is not higher than the first preset temperature, the circulating cooling is stopped and the next stage is entered; if the difference between the temperature in the adsorption tower and the temperature at the system exhaust port (2) is not higher than the second preset temperature when the circulating cooling is stopped, step S5 is no longer executed.

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