Energy-saving operation method of a regenerative adsorption dryer

Abstract

This invention discloses an energy-saving operation method for a regenerative adsorption dryer. A flow meter is installed at the main outlet of the regenerative adsorption dryer, and a dew point sensor is installed at the dry gas outlet. The flow meter detects the instantaneous and cumulative flow of the qualified gas after adsorption treatment in real time. The dew point sensor detects the dew point value of the gas produced by the dryer in real time. The maximum cumulative flow value for a single tower adsorption is set, as are the dew point control temperature and the high dew point alarm value. The maximum adsorption time for a single tower is also set. The switching conditions between the regeneration tower and the drying tower are set as follows: ① when the detected cumulative flow reaches the set maximum cumulative flow value; ② when the detected dew point value reaches the set dew point control temperature; ③ when the adsorption time of the adsorption tower reaches the maximum adsorption time. When the regeneration tower has completed the regeneration process and the drying tower meets any of the above conditions, the regeneration tower and the drying tower switch operation. This invention solves the problem of operational risks caused by dew point detection failure in existing technologies.

Description

Technical Field

[0001] This invention relates to an energy-saving operation method for a regenerative adsorption dryer, belonging to the field of energy management and energy-saving technology. Background Technology

[0002] Regenerative adsorption dryer systems are widely used in the post-treatment of compressed air systems in industrial and commercial fields. They mainly use a material (activated alumina) to adsorb moisture, which is packed into two towers, A and B. The towers A and B work alternately, one for drying the air and the other for regeneration (removing moisture), thereby achieving continuous and deep drying of compressed air. They are typically designed with a nominal pressure dew point of -40°C.

[0003] A complete compressed air system mainly consists of an air compressor, a regenerative adsorption dryer (or a refrigerated dryer), an air tank, filters, and end-user air equipment. When the end-user air consumption is large, the compressed air pressure will drop. When the air compressor detects that the pressure is lower than the set lower limit, the air compressor starts running and begins to produce compressed air. Once the pressure rises to the set upper limit, the air compressor automatically stops and enters standby mode, waiting for the pressure to drop to the lower limit again before restarting.

[0004] In a complete compressed air system, regenerative adsorption dryers commonly employ two regeneration methods: micro-heated compressed air regeneration and forced-air hot regeneration. Regarding control methods, two common modes are fixed-time control and dew-point control. Fixed-time control does not adjust to changes in dew point or air consumption fluctuations, consistently switching between adsorption and regeneration at a set time, thus resulting in higher energy consumption. In contrast, dew-point control can adjust the operating status according to actual dew point requirements, leading to greater energy savings. However, this mode relies heavily on the absolute reliability of the dew-point probe. If the dew-point probe fails or its data deviates, it will directly affect the dryer's control accuracy, unit energy consumption, and in severe cases, lead to unacceptable dew points, ultimately impacting product quality. Summary of the Invention

[0005] The purpose of this invention is to provide an energy-saving operation method for a regenerative adsorption dryer, in order to solve the technical problems of large energy waste in the existing control mode and the operational risks caused by dew point detection failure or data deviation.

[0006] The present invention adopts the following technical solution: an energy-saving operation method for a regenerative adsorption dryer, comprising the following steps: S1, installing a flow meter at the main outlet of the regenerative adsorption dryer and a dew point sensor at the dry gas outlet of the regenerative adsorption dryer; the flow meter detects the instantaneous and cumulative flow of the qualified gas after adsorption treatment in real time; the dew point sensor detects the dew point value of the gas produced by the dryer in real time; setting the maximum cumulative flow value for single-tower adsorption; setting the dew point control temperature and the dew point high temperature alarm value; setting the maximum adsorption time for a single tower; S2, setting the switching conditions between the regeneration tower and the drying tower as follows: ① when the detected cumulative flow reaches the set maximum cumulative flow value; ② when the detected dew point value reaches the set dew point control temperature; ③ when the adsorption time of the adsorption tower reaches the maximum adsorption time; S3, when the regeneration tower has completed the regeneration process and the drying tower meets any of the conditions in step S2, the regeneration tower and the drying tower switch operation; when the regeneration tower has not completed the regeneration process, the drying tower remains in operation; S4, after the regeneration tower and the drying tower switch, the cumulative flow of the original adsorption tower is cleared to zero, and the cumulative flow of the original regeneration tower is calculated.

[0007] Before operating the regenerative adsorption dryer, start the air compressor first. When the compressed air inlet pressure of the air compressor is detected to be greater than the set start pressure value, the regenerative adsorption dryer will start running. During the operation of the regenerative adsorption dryer, a low-pressure alarm value for compressed air is set. When the compressed air inlet pressure of the air compressor is lower than the low-pressure alarm value, the regenerative adsorption dryer will issue an alarm. The lower limit setting value for air compressor operation is greater than the low-pressure alarm value for compressed air, which is greater than the start pressure value.

[0008] When the compressed air inlet pressure of the air compressor is detected to be lower than the set start pressure value, the regenerative adsorption dryer will fail to start when the system start button is clicked, and a low air pressure fault will be displayed; the lower limit start value is set to 0.5 MPa.

[0009] Both towers of the adsorption dryer are equipped with air exhaust valves at the bottom. A drainage time interval is set. During the adsorption process in the adsorption tower, the air exhaust valves are opened at the set drainage time interval to drain the water accumulated at the bottom of the adsorption tower. The air exhaust valves are opened for 2 seconds.

[0010] The process of switching the regeneration tower to the adsorption tower includes three stages: (1) The first stage is the pressurization stage. The pressure inside the original regeneration tower is zero. The exhaust valve at the bottom of the original regeneration tower is closed, and the gas enters the tower through the regeneration regulating valve at the top of the original regeneration tower. The pressure inside the original regeneration tower gradually rises to be consistent with the pressure at the total outlet. (2) The second stage is the pressure equalization of the two towers: the inlet valve at the bottom of the original regeneration tower is opened, so that the regeneration tower and the adsorption tower are in adsorption mode at the same time to balance the pressure. (3) The third stage is the normal adsorption state. The original regeneration tower is switched to the adsorption tower, and the original adsorption tower is switched to the regeneration tower.

[0011] After the pressure equalization of the two towers reaches the set time, if the detected outlet dew point value is within the set acceptable range, it enters the normal adsorption state; if the detected outlet dew point value is not within the set acceptable range, the pressure equalization continues.

[0012] The operation process after the adsorption tower is switched to the regeneration tower is divided into four stages: (1) The first stage is venting and depressurization. The bottom air inlet valve of the regeneration tower is closed, the air outlet valve is opened, and the gas in the regeneration tower is discharged to make the pressure of the regeneration tower return to zero; (2) The second stage is heating and backflushing: the gas enters the electric heater through the regeneration valve at the top of the regeneration tower and is heated. Then it enters the tower from the top and blows the moisture in the packing in the form of backflushing to achieve regeneration; (3) The third stage is cooling: after the heating stage is completed, the electric heater stops heating and the adsorption tower is continuously cooled; (4) The fourth stage is waiting stage: when the first three stages are completed and the three switching conditions of dew point, flow rate and adsorption time in step S2 are not triggered, the air inlet valve and exhaust valve of the tower body are kept closed and waiting for the switching command. After the command is triggered, it enters the adsorption state.

[0013] The heating temperature inside the regeneration tower is set between 140 and 160°C. When the temperature inside the regeneration tower exceeds 200°C, a high-temperature alarm is triggered. The heating time accounts for half of the entire regeneration stage.

[0014] The regeneration tower is equipped with a silencer at its regeneration gas outlet to reduce exhaust noise. Part of the dry gas in the drying tower is depressurized by a throttling orifice plate and then heated by an electric heater before entering the regeneration tower for heating and regeneration.

[0015] During the operation of the regenerating adsorption dryer, the dew point and flow rate data are recorded to form dynamic data and dew point and flow rate curves.

[0016] The beneficial effects of this invention are as follows: The flow meter at the main outlet of this invention performs real-time instantaneous and cumulative flow detection on the qualified gas after adsorption treatment. The instantaneous flow rate can reflect the gas consumption at the end and the gas production of the air compressor in real time, and can also monitor the cumulative flow of the adsorption tower under adsorption conditions. When the cumulative flow of the corresponding single adsorption tower reaches the preset cumulative flow set value, the system will trigger the A / B tower switching process. For example, if the initial state is A tower adsorption and B tower regeneration, after the switch it becomes B tower adsorption and A tower regeneration. After the switching process is completed, the original cumulative flow of A tower is reset to zero, and the cumulative flow of B tower is accumulated.

[0017] This invention installs a dew point sensor at the main gas outlet to detect the quality of the gas produced by the dryer. During operation, when the detected dew point value reaches the set dew point control temperature, the system will trigger a switching process between towers A and B. For example, if the initial state is tower A adsorption and tower B regeneration, the switching will change to tower B adsorption and tower A regeneration. If the detected dew point value reaches the set high-temperature dew point alarm value during operation, the system will trigger a dew point non-compliance alarm, but the dryer will not perform a shutdown or switching operation, maintaining its original control logic. It should be noted that the set value of the dew point control temperature should be lower than the set value of the high-temperature dew point alarm.

[0018] During single-tower adsorption, if the system remains in a state of extremely low gas consumption for an extended period, causing the cumulative flow and dew point temperature of the single tower to fail to reach the set values ​​for triggering switching, the single tower will remain in adsorption mode for an extended period, posing a risk of packing damage. Therefore, this invention incorporates a maximum adsorption time protection, i.e., setting a maximum adsorption time limit. When the adsorption time of a single tower reaches this limit, the system will trigger the A / B tower switching process to ensure safe operation of the equipment.

[0019] This invention dynamically adjusts the switching control conditions of the regenerative adsorption dryer based on the actual gas consumption and dew point at the end, thereby minimizing ineffective regeneration energy consumption and improving the control accuracy of the dryer. It also solves the operational risks caused by dew point detection failure or data deviation in existing technologies.

[0020] As a preferred solution, the air compressor should be started before the compressed air system is put into operation. The regenerative adsorption dryer can only start operation after detecting that the system pressure has reached the lower limit for starting. To protect the dryer from the risk of the pneumatic solenoid valve malfunctioning and the electric heater being damaged if started directly without air supply, the starting conditions for the dryer are increased: if the pressure is below 0.5 MPa, the adsorption dryer cannot start, and a low air pressure fault will be displayed when the start button is pressed. During operation, the dryer has a low compressed air pressure alarm setting; when this value is reached, an alarm will be triggered.

[0021] As a preferred embodiment, the present invention incorporates a drainage interval control at the bottom of the adsorption tower. During the adsorption process, a large amount of adsorbed moisture accumulates at the bottom of the tower. To prevent damage to the bottom packing material due to prolonged dampness, the control system automatically opens the corresponding air exhaust valve at the bottom at set time intervals and continuously discharges for 2 seconds to remove the accumulated moisture. This interval can be flexibly set according to factors such as the size of the dryer and the adsorption time.

[0022] As a preferred option, the process of switching the regeneration tower to the adsorption tower is divided into three stages: pressurization, pressure equalization, and normal adsorption. The pressurization stage is to avoid high pressure impact, protect the adsorbent and valves, close the exhaust valve at the bottom of the tower, and allow the gas to slowly enter the tower through the regeneration regulating valve. The pressure gradually rises to match the outlet pressure. The pressurization time can be set freely (for example, if 1 minute is actually needed, then set to 1 minute). The pressure equalization stage is to ensure a smooth switch and maintain a stable dew point of the downstream gas supply. The inlet valve at the bottom of the original regeneration tower is opened, so that both towers are in adsorption mode at the same time to balance the pressure.

[0023] As a preferred option, the pressurization time can be set freely. For example, if 1 minute is actually needed, then set it to 1 minute. The equalization time can be flexibly set according to the changes in dew point temperature during this stage. For example, after setting 2 minutes of equalization, the original adsorption tower is switched to the regeneration tower. If the outlet dew point is stable within the qualified range, then the parameters are appropriate. If the deviation is large, the equalization time should be increased appropriately.

[0024] As a preferred option, the process of switching the adsorption tower to the regeneration tower is divided into four stages: venting and depressurization, heating and backflushing, cooling, and waiting. Venting and depressurization is to discharge the gas in the original adsorption tower so that the tower pressure is reduced to zero. Heating and backflushing is to pass the gas into an electric heater to heat it and then send it into the tower to dry the moisture in the packing in the form of backflushing, thereby achieving regeneration.

[0025] As a preferred option, the heater operates automatically based on the temperature, which is usually set between 140 and 160°C. If the temperature exceeds 200°C, it indicates that the regeneration valve opening is too small and the heater heat cannot be effectively removed, and the system will trigger a high-temperature alarm. The heating time can be set freely and usually accounts for half of the entire regeneration stage. The cooling time can also be set freely and is usually close to half of the entire regeneration stage.

[0026] As a preferred solution, the operating data of the regenerative adsorption dryer is generated by real-time detection of dew point and cumulative flow, forming dynamic data and operating curves. Users can view historical operating data, including the changing trends of dew point and cumulative flow throughout the day, through a touch screen interface connected to the system. The system can also distinguish whether the data corresponds to the adsorption state of tower A or tower B, which facilitates the analysis of gas usage and troubleshooting after a fault occurs. Attached Figure Description

[0027] Figure 1 This is a standard configuration diagram of a compressed air regeneration adsorption drying system; Figure 2 This is a schematic diagram of the compressed air regeneration adsorption dryer used in an embodiment of the present invention.

[0028] In the diagram: 1-Air compressor, 2-Air storage tank, 3-Class C precision filter, 4-Class A precision filter, 5-Regenerative adsorption dryer, 6-Class T precision filter, AD1-Left tower, AD2-Right tower, 7-Dew point sensor, 8-Flow meter, 9-Electric heater, 10-Throttle orifice plate, 11-Silencer, 12-Controller, 13-Pressure reducing filter, V11-Left air inlet valve, V12-Right air inlet valve, V13-Left regenerated gas outlet check valve, V14-Right regenerated gas outlet check valve, V15-Regenerated gas regulating valve, V17-Left regenerated gas inlet check valve, V18-Right regenerated gas inlet check valve, V19-Left air exhaust valve, V20-Right air exhaust valve. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0030] The energy-saving operation method of the regenerative adsorption dryer of this invention adopts Figure 1 The compressed air regeneration adsorption drying system is used. The system includes, in sequence, an air compressor 1, an air storage tank 2, a C-stage precision filter 3, an A-stage precision filter 4, a regeneration adsorption dryer 5, and a T-stage precision filter 6. Air compressed by the air compressor 1 is stored in the air storage tank 2. After passing through two stages of precision filtration, the air enters the compressed air regeneration adsorption dryer 1 for drying. The dried gas then passes through the T-stage precision filter 6 to obtain the dried air product. The compressed air regeneration adsorption dryer... Figure 2 As shown, it consists of two towers, one for adsorption and the other for drying.

[0031] An embodiment of the present invention provides an energy-saving operation method for a regenerative adsorption dryer, comprising the following steps: S1, installing a flow meter 8 at the main outlet of the regenerative adsorption dryer, and installing a dew point sensor 7 at the dry gas outlet of the regenerative adsorption dryer; the flow meter 8 detects the instantaneous flow and cumulative flow of the qualified gas after adsorption treatment in real time; the dew point sensor 7 detects the dew point value of the gas produced by the dryer in real time; setting the maximum cumulative flow value of single-tower adsorption; setting the dew point control temperature and the dew point high temperature alarm value; and setting the maximum adsorption time of a single tower. S2. The conditions for switching between the regeneration tower and the drying tower are set as follows: ① When the detected cumulative flow reaches the set maximum cumulative flow value; ② When the detected dew point value reaches the set dew point control temperature; ③ When the adsorption time of the adsorption tower reaches the maximum adsorption time. S3. When the regeneration tower has completed the regeneration process and the drying tower meets any of the conditions in step S2, the regeneration tower and the drying tower switch operation; when the regeneration tower has not completed the regeneration process, the drying tower remains in operation. S4. After switching between the regeneration tower and the drying tower, the cumulative flow of the original adsorption tower is reset to zero, and the cumulative flow of the original regeneration tower is calculated.

[0032] Before operating the regenerative adsorption dryer, start the air compressor. The dryer will start operating once the compressed air inlet pressure exceeds the set start-up pressure. During operation, a low-pressure alarm value for compressed air is set. If the compressed air inlet pressure falls below this value, the dryer will issue an alarm. The lower limit for air compressor operation is set to be greater than the low-pressure alarm value and then greater than the start-up pressure. If the compressed air inlet pressure is less than the set start-up pressure, the dryer will fail to start and will display a low pressure fault message when the system start button is pressed. The lower start-up limit is set to 0.5 MPa.

[0033] Both towers of the regenerative adsorption dryer are equipped with air exhaust valves at the bottom. A drainage time interval is set. During the adsorption process in the adsorption tower, the corresponding air exhaust valve is opened at the set drainage time interval to drain the water accumulated at the bottom of the adsorption tower. The air exhaust valve opens for 2 seconds.

[0034] The process of switching the regeneration tower to the adsorption tower includes three stages: (1) The first stage is the pressurization stage. The pressure inside the original regeneration tower is zero. The exhaust valve at the bottom of the original regeneration tower is closed, and the gas enters the tower through the regeneration regulating valve at the top of the original regeneration tower. The pressure inside the original regeneration tower gradually rises to match the pressure at the total outlet. (2) The second stage is the pressure equalization of the two towers: the inlet valve at the bottom of the original regeneration tower is opened, so that the regeneration tower and the adsorption tower are simultaneously in adsorption mode to balance the pressure. (3) The third stage is the normal adsorption state. The original regeneration tower is switched to the adsorption tower, and the original adsorption tower is switched to the regeneration tower. After the pressure equalization of the two towers reaches the set time, if the detected outlet dew point value is within the set qualified range, the normal adsorption state is entered. If the detected outlet dew point value is not within the set qualified range, the pressure equalization continues.

[0035] The operation process after the adsorption tower is switched to the regeneration tower is divided into four stages: (1) The first stage is venting and depressurization. The bottom air inlet valve of the regeneration tower is closed, the air outlet valve is opened, and the gas in the regeneration tower is discharged to make the pressure of the regeneration tower return to zero; (2) The second stage is heating and backflushing: the gas enters the electric heater through the regeneration valve at the top of the regeneration tower and is heated. Then it enters the tower from the top and blows the moisture in the packing in the form of backflushing to achieve regeneration; the heating temperature in the regeneration tower is set between 140 and 160°C. When the temperature in the regeneration tower exceeds 200°C, a high temperature alarm is triggered; the heating time accounts for half of the entire regeneration stage; (3) The third stage is cooling: after the heating stage is completed, the electric heater stops heating and the adsorption tower is continuously cooled; (4) The fourth stage is waiting stage: when the first three stages are completed and the three switching conditions of dew point, flow rate and adsorption time in step S2 are not triggered, the air inlet valve and exhaust valve of the tower body are kept closed and waiting for the switching command. After the command is triggered, it enters the adsorption state.

[0036] The regeneration tower's regeneration gas outlet is connected to a silencer 11 to reduce exhaust noise. Part of the dry gas in the drying tower is depressurized by a throttling orifice plate 10 before entering an electric heater 9 for heating, and then regenerating in the regeneration tower. During operation of the regeneration adsorption dryer, dew point and flow rate data are recorded to generate dynamic data and dew point and flow rate curves.

[0037] In this invention, before starting the regenerative adsorption dryer, two operating modes can be selected: adsorption in tower A and regeneration in tower B, or adsorption in tower B and regeneration in tower A. Before starting the dryer, the operator can select adsorption to be performed in tower A or tower B via the interface. If tower A is selected, tower A will perform the adsorption process and tower B will perform the regeneration process after startup; if tower B is selected, the process is reversed. This design effectively avoids the situation of repeated adsorption in a single tower when restarting after shutdown due to maintenance, debugging, etc., thereby preventing damage to the packing material inside the tower.

[0038] In the adsorption process of a regenerative adsorption dryer, compressed air produced by an air compressor enters through the inlet valve at the bottom of the adsorption tower, flows through the packing layer inside the tower for adsorption treatment, and the compressed air that meets the qualified standards is discharged from the outlet at the top of the tower. The "nominal inlet volumetric flow rate" (e.g., "23 m³ / min") marked on the equipment nameplate is the dryer's instantaneous maximum compressed air processing capacity. Taking 23 m³ / min as an example, the maximum instantaneous processing capacity of this equipment is 23 m³ / min. The adsorption capacity of a single tower in the adsorption process depends on the amount of packing material inside the tower. If the maximum adsorption time is set to 2 hours at the factory, then the total amount of compressed air cumulatively processed by a single tower during the adsorption stage is: 23 m³ / min × 120 min = 2760 m³.

[0039] A specific embodiment of the energy-saving operation method for the regenerative adsorption dryer of the present invention is as follows: The specific steps for real-time monitoring of the dryer's outlet flow rate, outlet dew point, heater temperature, and compressed air inlet pressure, and for control based on the dryer's operating procedures and the monitored data, are as follows: 1. When the compressed air inlet pressure is lower than P1 (starting pressure value, 0.5MPa), the regenerative adsorption dryer cannot start operation; during operation, when the pressure is lower than P2 (compressed air low pressure alarm value, set according to the actual air compressor supply pressure), the compressed air low pressure alarm function is triggered.

[0040] 2. Adsorption termination trigger switching conditions: ① When the outlet flow rate detects that the cumulative flow rate reaches Q1 (the maximum cumulative flow rate for single-tower adsorption); ② When the outlet dew point detects that the dew point temperature reaches Td1 (the dew point control temperature); ③ When the adsorption time reaches t1 (the longest adsorption time for a single tower, set according to actual conditions). If any of conditions ①②③ is met, the switching is triggered, provided the regeneration tower has completed the entire regeneration process. An alarm is triggered when the outlet dew point detects that the dew point temperature reaches Td2 (the high-temperature dew point alarm value).

[0041] 3. In the dryer, towers A and B are used alternately. During the switching time, one tower is in adsorption while the other tower is in regeneration / waiting mode. The working sequence is as follows: Figure 2 , Figure 2 The left column AD1 is an adsorption column, and the right column AD2 is a regeneration column.

[0042] 4. Adsorption: When the adsorption tower is working, air enters the adsorption bed through the left air inlet valve V11, and then exits the system through the left regeneration gas outlet check valve V13. During the adsorption process, according to the set discharge time t2 (which can be freely set according to the length of adsorption and the load), the left air exhaust valve V19 opens for 2 seconds to discharge the water vapor accumulated in the tower.

[0043] 5. Regeneration: The regeneration of the adsorption tower consists of four steps, namely, depressurization, heating, cooling, and waiting.

[0044] (1) Venting: Left tower AD1 enters adsorption, and right tower AD2 enters regeneration. Open the right air exhaust valve V20 to discharge the remaining pressurized air in right tower AD2. The venting time is t3 (set according to the time when the venting pressure returns to zero).

[0045] (2) Heating: After venting, the right tower AD2 enters the heating stage. Start the electric heater 9. A small portion of dry air from the main dry air pipe is used as regeneration gas. After being depressurized to near atmospheric pressure via the regeneration gas regulating valve V15 and the orifice plate 10, it enters the electric heater 9, heating the regeneration gas to temperature T1. The regeneration gas passes through the regeneration gas flow path, and due to the pressure difference, the right regeneration gas inlet check valve V18 automatically opens, entering the adsorbent bed of the right tower to heat and desorb the adsorbent. The desorbed moisture is discharged into the atmosphere along with the regeneration gas through the right air exhaust valve V20. During the heating stage, the heating and regeneration temperature is controlled between T1 and T2 (reaching T3 triggers an over-temperature alarm), and the heating time is controlled at t4 (approximately halved based on the regeneration time). When the heating time ends, turn off the electric heater 9. T1 is typically 140℃, T2 is typically 160℃, and T3 is typically 200-230℃.

[0046] (3) Cooling: After heating ends, the cooling stage begins. Dry air is still used for the regeneration gas, and the regeneration gas flow path is the same as that in the heating stage. The regeneration gas enters the adsorption bed of the right tower to cool the heated adsorption bed so that it can be put into adsorption operation. The cooling time is controlled at t5 (set by halving the regeneration time). When the cooling time is up, the cooling ends.

[0047] (4) Waiting: After all three steps of regeneration are completed, if the A / B tower switching command is not triggered, the right air exhaust valve V20 and the right air intake valve V12 will be closed.

[0048] 6. Adsorption: The adsorption process in the adsorption tower consists of three steps, namely pressurization, pressure equalization between the two towers, and adsorption.

[0049] (1) Pressurization: When the right tower AD2 is about to enter the next adsorption time, the right tower AD2 under normal pressure must be pressurized from normal pressure to the adsorption working pressure. The method is to close the right air exhaust valve V20, and the air will still automatically pressurize from the left tower AD1 to the right tower AD2 through the regeneration gas flow path. The pressurization time t6 (set according to the actual pressurization pressure and duration).

[0050] (2) Pressure equalization between the two towers: The air pressure in the two towers reaches equilibrium at this time, and the switching conditions are met. The pressure equalization time is controlled at time t7 (set according to the switching dew point stabilization time). Before the adsorption time ends, the right air inlet valve V12 is opened in advance of time C1. At this time, the right regeneration gas outlet check valve V14 is automatically opened by means of the pressure difference.

[0051] (3) Adsorption: When the right tower AD2 is regenerated, the adsorption work of the left tower AD1 is completed. The two towers are switched to use. The left air inlet valve V11 is closed. At this time, the two towers have completed the switch and entered the next cycle.

[0052] This invention controls the operation of the regenerative adsorption dryer dynamically, based on the actual gas consumption and dew point at the end, to minimize ineffective regeneration energy consumption.

Claims

1. An energy-saving operation method for a regenerative adsorption dryer, characterized in that, It includes the following steps: S1. Install a flow meter at the main outlet of the regenerative adsorption dryer and a dew point sensor at the dry gas outlet of the regenerative adsorption dryer. The flow meter detects the instantaneous and cumulative flow of the qualified gas after adsorption treatment in real time. The dew point sensor detects the dew point value of the gas produced by the dryer in real time. Set the maximum cumulative flow value of single tower adsorption, set the dew point control temperature and the dew point high temperature alarm value; set the maximum adsorption time of a single tower. S2. The conditions for switching between the regeneration tower and the drying tower are set as follows: ① When the detected cumulative flow reaches the set maximum cumulative flow value; ② When the detected dew point value reaches the set dew point control temperature. ③ When the adsorption time of the adsorption tower reaches the maximum adsorption time; S3. When the regeneration tower has completed the regeneration process and the drying tower meets any of the conditions in step S2, the regeneration tower and the drying tower switch to operation; when the regeneration tower has not completed the regeneration process, the drying tower remains in operation; S4. After the regeneration tower and the drying tower switch, the cumulative flow of the original adsorption tower is reset to zero, and the cumulative flow of the original regeneration tower is calculated.

2. The energy-saving operation method of the regenerative adsorption dryer according to claim 1, characterized in that: Before operating the regenerative adsorption dryer, start the air compressor first. When the compressed air inlet pressure of the air compressor is detected to be greater than the set start pressure value, the regenerative adsorption dryer will start running. During the operation of the regenerative adsorption dryer, a low-pressure alarm value for compressed air is set. When the compressed air inlet pressure of the air compressor is lower than the low-pressure alarm value, the regenerative adsorption dryer will issue an alarm. The lower limit setting value for air compressor operation is greater than the low-pressure alarm value for compressed air, which is greater than the start pressure value.

3. The energy-saving operation method of the regenerative adsorption dryer according to claim 1, characterized in that: When the compressed air inlet pressure of the air compressor is detected to be lower than the set start pressure value, the regenerative adsorption dryer will fail to start when the system start button is clicked, and a low air pressure fault will be displayed; the lower limit start value is set to 0.5 MPa.

4. The energy-saving operation method of the regenerative adsorption dryer according to claim 1, characterized in that: Both towers of the regenerative adsorption dryer are equipped with air exhaust valves at the bottom. A drainage time interval is set. During the adsorption process in the adsorption tower, the air exhaust valves are opened at the set drainage time interval to drain the water accumulated at the bottom of the adsorption tower. The air exhaust valves are opened for 2 seconds.

5. The energy-saving operation method of the regenerative adsorption dryer according to claim 1, characterized in that: The process of switching the regeneration tower to the adsorption tower includes three stages: (1) The first stage is the pressurization stage. The pressure inside the original regeneration tower is zero. The exhaust valve at the bottom of the original regeneration tower is closed, and the gas enters the tower through the regeneration regulating valve at the top of the original regeneration tower. The pressure inside the original regeneration tower gradually rises to be consistent with the pressure at the total outlet. (2) The second stage is the pressure equalization of the two towers: the inlet valve at the bottom of the original regeneration tower is opened, so that the regeneration tower and the adsorption tower are in adsorption mode at the same time to balance the pressure. (3) The third stage is the normal adsorption state. The original regeneration tower is switched to the adsorption tower, and the original adsorption tower is switched to the regeneration tower.

6. The energy-saving operation method of the regenerative adsorption dryer according to claim 5, characterized in that: After the pressure equalization of the two towers reaches the set time, if the detected outlet dew point value is within the set acceptable range, it enters the normal adsorption state; if the detected outlet dew point value is not within the set acceptable range, the pressure equalization continues.

7. The energy-saving operation method of the regenerative adsorption dryer according to claim 1, characterized in that: The operation process after the adsorption tower is switched to the regeneration tower is divided into four stages: (1) The first stage is venting and depressurization. The bottom air inlet valve of the regeneration tower is closed, the air outlet valve is opened, and the gas in the regeneration tower is discharged to make the pressure of the regeneration tower return to zero; (2) The second stage is heating and backflushing: the gas enters the electric heater through the regeneration valve at the top of the regeneration tower and is heated. Then it enters the tower from the top and blows the moisture in the packing in the form of backflushing to achieve regeneration; (3) The third stage is cooling: after the heating stage is completed, the electric heater stops heating and the adsorption tower is continuously cooled; (4) The fourth stage is waiting stage: when the first three stages are completed and the three switching conditions of dew point, flow rate and adsorption time in step S2 are not triggered, the air inlet valve and exhaust valve of the tower body are kept closed and waiting for the switching command. After the command is triggered, it enters the adsorption state.

8. The energy-saving operation method of the regenerative adsorption dryer according to claim 7, characterized in that: The heating temperature inside the regeneration tower is set between 140 and 160°C. When the temperature inside the regeneration tower exceeds 200°C, a high-temperature alarm is triggered. The heating time accounts for half of the entire regeneration stage.

9. The energy-saving operation method of the regenerative adsorption dryer according to claim 7, characterized in that: The regeneration tower is equipped with a silencer at its regeneration gas outlet to reduce exhaust noise. Part of the dry gas in the drying tower is depressurized by a throttling orifice plate and then heated by an electric heater before entering the regeneration tower for heating and regeneration.

10. The energy-saving operation method of the regenerative adsorption dryer according to claim 1, characterized in that: During the operation of the regenerating adsorption dryer, the dew point and flow rate data are recorded to form dynamic data and dew point and flow rate curves.

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