An intelligent start-stop pressure swing adsorption hydrogen production system and its start-stop method

Abstract

The present invention discloses an intelligent start-stop pressure swing adsorption hydrogen production system and a start-stop method thereof, which solves the technical problem that the start-stop operation is cumbersome and complicated in the prior art, resulting in a long start-stop time. The pressure swing adsorption hydrogen production system includes a raw gas transmission pipe, an adsorption tower group, a reverse pressure reduction pipe, a flushing outlet pipe, a product gas external transmission pipe, a first equalization and final charging program-controlled valve pipeline, a pressure equalization program-controlled valve pipeline, a forward flushing program-controlled valve pipeline, a control system, a final charging pipeline, a final charging regulating valve HV101, a venting pipeline, a product gas venting regulating valve PV101, an adjustable program-controlled valve HV102, an adjustable program-controlled valve HV103, a program-controlled valve KV102 and a program-controlled valve KV101. The start-stop method mainly controls the regeneration, equalization and charging of the corresponding adsorption tower through the control system, and controls the automatic pressure relief, automatic pressure increase and automatic operation of the corresponding adsorption tower. The present invention can realize intelligent start and stop of the system and utilize the hydrogen produced by itself to maintain the system pressure, thereby eliminating the nitrogen replacement step and the replacement of nitrogen. After the pressure swing adsorption hydrogen production system is started up, the product hydrogen can be quickly qualified.

Description

Technical Field

[0001] The present invention belongs to the technical field of pressure swing adsorption gas separation, and in particular relates to an intelligent start-stop pressure swing adsorption hydrogen production system and a start-stop method thereof. Background Art

[0002] Pressure swing adsorption hydrogen production technology uses the characteristics that the adsorption capacity of the adsorbent for non-hydrogen impurities is greater than the adsorption capacity of hydrogen, and the adsorption capacity increases with the increase of pressure and decreases with the decrease of pressure to purify hydrogen. Pressure swing adsorption hydrogen production technology has been widely used in various fields such as metallurgy, chemical industry, and energy. The pressure swing adsorption hydrogen separation process does not have temperature changes and can be completed at room temperature. The hydrogen purity is high and the operation is simple. It is currently the most widely used hydrogen purification method.

[0003] The application scenarios of pressure swing adsorption hydrogen production generally require the continuous operation time of the device to be as long as possible and the start-up and shutdown time to be as short as possible. Therefore, the configuration of the adsorbent and programmable valve of pressure swing adsorption can meet the requirements of long-term operation of the device. The maintenance cycle of petrochemical devices is 3 to 5 years, and general pressure swing adsorption hydrogen production devices are only started and stopped during maintenance.

[0004] The adsorbent of pressure swing adsorption hydrogen production is easily contaminated and damaged during parking, which affects the separation effect of the device when it is driven next time. Therefore, the pressure swing adsorption device needs to be depressurized after parking, and then replaced with nitrogen, and then nitrogen is used to maintain pressure after replacement. A general pressure swing adsorption device has 4 to 12 adsorption towers. After each adsorption tower is depressurized, nitrogen replacement and pressurization operations are carried out in turn. The process is cumbersome, time-consuming, and there are many manual operations. For some pressure swing adsorption hydrogen production devices that need to be parked frequently, such as pressure swing adsorption hydrogen production devices for producing fuel hydrogen for proton exchange membrane fuel cell vehicles, since there is no demand for hydrogenation at night, the demand for hydrogen is mainly concentrated during the day. The pressure swing adsorption device that provides the hydrogen source needs to be driven during the day and parked at night. Even in some areas, due to the relatively small demand for hydrogen, the hydrogen production of one day can meet the demand for several days, and the pressure swing adsorption hydrogen production device needs to be started and stopped frequently. If the traditional start-stop method of the pressure swing adsorption device is adopted, each start-stop takes a long time and the operation is complicated.

[0005] Therefore, designing an intelligent start-stop pressure swing adsorption hydrogen production system and its start-stop method, converting the original start-stop operation that requires manual operation into a process of automatic judgment and execution by the program, realizing the intelligent start-stop of the pressure swing adsorption hydrogen production device, and using the hydrogen produced by the device itself to maintain the pressure of the device, eliminating the nitrogen replacement step and replacement of nitrogen, has become a technical problem that needs to be urgently solved by technicians in the relevant technical field. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an intelligent start-stop pressure swing adsorption hydrogen production system and a start-stop method thereof, so as to solve the technical problem that the start-stop operation of the prior art is cumbersome and complicated, resulting in a long start-stop time.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] An intelligent start-stop pressure swing adsorption hydrogen production system comprises a raw gas transmission pipe, an adsorption tower group, a reverse pressure reducing pipe, a flushing outlet pipe, a product gas transmission pipe, an equalizing and final charging program-controlled valve pipeline, a pressure equalizing program-controlled valve pipeline, a forward flushing program-controlled valve pipeline, and a control system for controlling the operation of the hydrogen production system; a final charging pipeline is connected between the equalizing and final charging program-controlled valve pipeline and the product gas transmission pipe, a final charging regulating valve HV101 is provided on the final charging pipeline, a venting pipeline is connected to the product gas transmission pipe, a product gas venting regulating valve PV101 is provided on the venting pipeline, an adjustable program-controlled valve HV102 is provided on the raw gas transmission pipe, an adjustable program-controlled valve HV103 is provided on the reverse pressure reducing pipe, a program-controlled valve KV102 is provided on the flushing outlet pipe, and a program-controlled valve KV101 is provided on the product gas transmission pipe.

[0009] Further, the control system is respectively connected to the final filling regulating valve HV101, the product gas venting regulating valve PV101, the adjustable program-controlled valve HV102, the adjustable program-controlled valve HV103, the program-controlled valve KV102 and the program-controlled valve KV101.

[0010] Furthermore, the adsorption tower group is provided with a pressure detection instrument for detecting the gas pressure in the adsorption tower.

[0011] Furthermore, a raw gas flow meter FQ101 connected to the control system is provided on the raw gas delivery pipe.

[0012] Furthermore, a product gas programmable valve connected to the control system is provided between the product gas transmission pipe and the adsorption tower group; preferably, a raw gas programmable valve connected to the control system is provided between the raw gas transmission pipe and the adsorption tower group.

[0013] Furthermore, a reverse pressure reduction program-controlled valve pipeline is provided between the adsorption tower group and the reverse pressure reduction pipe; preferably, a flushing outlet program-controlled valve pipeline is provided between the adsorption tower group and the flushing outlet pipe.

[0014] Furthermore, a product gas quality online detection instrument R101 connected to the control system is provided on the product gas transmission pipeline.

[0015] A parking method for an intelligent start-stop pressure swing adsorption hydrogen production system comprises the following steps:

[0016] Step 1, adsorbent regeneration: the control system first controls the adjustable program-controlled valve HV102 and the program-controlled valve KV101 to close, and then changes the next sub-cycle time to the time when the half-load operation is continued to run until each adsorption tower in the adsorption tower group is flushed and stops;

[0017] Step 2, pressure equalization of the adsorption tower group: after the adsorption tower group completes the regeneration of the adsorption tower, the control system detects the adsorption tower in the adsorption step and the final filling step, or detects the adsorption tower in the adsorption step, the first pressure equalization step and the first pressure equalization step, and opens an equalization valve corresponding to the adsorption tower in the above steps for pressure equalization. After the pressure equalization is completed, the corresponding equalization valve is closed and the product gas program-controlled valve and the final filling regulating valve corresponding to the adsorption tower in the above steps are opened;

[0018] Step 3, pressurizing the adsorption tower group: the control system detects the adsorption towers that are in the steps that require pressure boosting, i.e., the forward step, the reverse step and the flushing step, and opens the final charging programmable valves corresponding to the above-mentioned adsorption towers to boost their pressure. When their pressure rises to the set value, the corresponding final charging programmable valves are closed until the pressure in all the adsorption towers that are in the reverse step or the flushing step reaches or exceeds the set value. The control system controls the final charging regulating valve HV101 and all the programmable valves to close, and the system automatically stops.

[0019] Furthermore, in step 2, the pressure equalization time of the adsorption tower in the adsorption step and the final charging step, or the adsorption tower in the adsorption step, the first pressure equalization step and the first pressure drop step is 1 minute when the pressure equalization valve is opened for pressure equalization; preferably, in step 2, the opening of the charging regulating valve is set to 10% when the pressure is opened; more preferably, in step 3, the set value of the pressure increase of the adsorption tower in the step requiring pressure increase is 0.20MPaG; further preferably, if the sequential release step has not yet ended, the adsorption tower in the sequential release step does not need to be pressurized.

[0020] A method for starting an intelligent start-stop pressure swing adsorption hydrogen production system comprises the following steps:

[0021] Step A, automatic pressure relief: the control system opens the reverse pressure-reducing program-controlled valve corresponding to the adsorption tower that is detected to be in the step of pressure-raising when the pressure swing adsorption hydrogen production system is shut down, opens the adjustable program-controlled valve HV103 to the set opening to start pressure relief, and when the pressure drops to the regeneration pressure, closes the reverse pressure-reducing program-controlled valve, changes the adjustable program-controlled valve HV103 to full opening, and opens the program-controlled valve KV102;

[0022] Step B, automatic pressure increase: After completing the automatic pressure relief step in step A, the control system controls the valve switching of the pressure swing adsorption hydrogen production system to enter normal operation, and at the same time opens the adjustable program-controlled valve HV102 until the pressure in the adsorption tower reaches the pressure of the feed gas;

[0023] Step C, automatic operation: After completing the automatic pressure increase step in step B, open the product gas venting regulating valve PV101 to vent the product gas until the product hydrogen meets the index requirements, close the product gas venting regulating valve PV101, and open the product gas programmable valve on the product gas transmission pipe to output qualified product hydrogen.

[0024] Furthermore, in step A, the opening is set to 15%; preferably, in step B, when the control system controls the valve switching when the pressure swing adsorption hydrogen production system enters normal operation, the cycle time of the pressure swing adsorption hydrogen production system remains the cycle time at half load; more preferably, in step B, after opening the adjustable program-controlled valve HV102, the adjustable program-controlled valve HV102 needs to be gradually opened from zero opening to 10% within 30s; further preferably, in step B, after opening the adjustable program-controlled valve HV102, the raw gas flow rate needs to be controlled at 30% according to the raw gas flowmeter FQ101.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention has a simple structure, a scientific and reasonable design, and is easy to use. It converts the process that originally required manual operation during start and stop operations into a process that is automatically judged and executed by the control system, thereby realizing the intelligent start and stop of the pressure swing adsorption hydrogen production system, and utilizing the hydrogen produced by the pressure swing adsorption hydrogen production system itself to maintain the system pressure, thereby eliminating the nitrogen replacement step and the replacement of nitrogen. After the pressure swing adsorption hydrogen production system is started, the product hydrogen can be quickly qualified, and it can effectively solve the technical problem of the prior art that the operation of start and stop is cumbersome and complicated, resulting in a long start and stop time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a system block diagram of the pressure swing adsorption hydrogen production system of the present invention.

[0028] Figure 2 It is a system block diagram of an 8-tower pressure swing adsorption hydrogen production system in an example of the present invention.

[0029] Figure 3 It is a system block diagram of a 10-tower pressure swing adsorption hydrogen production system in an example of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore they cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; of course, it can also be a mechanical connection or an electrical connection; in addition, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] like Figure 1 As shown, the present invention provides an intelligent start-stop pressure swing adsorption hydrogen production system, including a raw gas transmission pipe, an adsorption tower group, a reverse pressure reducing pipe, a flushing outlet pipe, a product gas transmission pipe, an equalizing and final charging programmable valve pipeline, a pressure equalizing programmable valve pipeline, a forward flushing programmable valve pipeline, and a control system for controlling the operation of the hydrogen production system, a final charging pipeline is connected between the equalizing and final charging programmable valve pipeline and the product gas transmission pipe, a final charging pipeline is provided with a final charging regulating valve HV101, a venting pipeline is connected to the product gas transmission pipe, a product gas venting regulating valve PV101 is provided on the venting pipeline, an adjustable programmable valve HV102 is provided on the raw gas transmission pipe, an adjustable programmable valve HV103 is provided on the reverse pressure reducing pipe, a programmable valve KV102 is provided on the flushing outlet pipe, and a programmable valve KV101 is provided on the product gas transmission pipe. The control system is respectively connected to the final filling regulating valve HV101, the product gas venting regulating valve PV101, the adjustable program-controlled valve HV102, the adjustable program-controlled valve HV103, the program-controlled valve KV102 and the program-controlled valve KV101.

[0034] The pressure swing adsorption hydrogen production system of the present invention is provided with an adsorption tower group with a pressure detection instrument for each adsorption tower, and a raw gas flow meter FQ101 connected to the control system is provided on the raw gas delivery pipe. A product gas program-controlled valve connected to the control system is provided between the product gas delivery pipe and the adsorption tower group. An online product gas quality detection instrument R101 connected to the control system is provided on the product gas delivery pipe. A raw gas program-controlled valve connected to the control system is provided between the raw gas delivery pipe and the adsorption tower group. A reverse pressure reduction program-controlled valve pipeline is provided between the adsorption tower group and the reverse pressure reduction pipe. A flushing outlet program-controlled valve pipeline is provided between the adsorption tower group and the flushing outlet pipe.

[0035] The present invention has a simple structure, a scientific and reasonable design, and is easy to use. It converts the process that originally required manual operation during start and stop operations into a process that is automatically judged and executed by the control system, thereby realizing the intelligent start and stop of the pressure swing adsorption hydrogen production system, and utilizing the hydrogen produced by the pressure swing adsorption hydrogen production system itself to maintain the system pressure, thereby eliminating the nitrogen replacement step and the replacement of nitrogen. After the pressure swing adsorption hydrogen production system is started, the product hydrogen can be quickly qualified, and it can effectively solve the technical problem of the prior art that the operation of start and stop is cumbersome and complicated, resulting in a long start and stop time.

[0036] The present invention provides a parking method for an intelligent start-stop pressure swing adsorption hydrogen production system, comprising the following steps:

[0037] Step 1, adsorbent regeneration: the control system first controls the adjustable program-controlled valve HV102 and the program-controlled valve KV101 to close, and then changes the next sub-cycle time to the time when the half-load operation is continued until each adsorption tower in the adsorption tower group is flushed and stops;

[0038] Step 2, pressure equalization of the adsorption tower group: after the adsorption tower group completes the regeneration of the adsorption tower, the control system detects the adsorption tower in the adsorption step and the final filling step, or detects the adsorption tower in the adsorption step, the first pressure equalization step and the first pressure equalization step, and opens an equalization valve corresponding to the adsorption tower in the above steps for pressure equalization. After the pressure equalization is completed, the corresponding equalization valve is closed and the product gas program-controlled valve and the final filling regulating valve corresponding to the adsorption tower in the above steps are opened;

[0039] Step 3, pressurizing the adsorption tower group: the control system detects the adsorption towers that are in the step requiring pressurization, i.e., the forward release step (if the forward release step has not yet ended, the adsorption towers in the forward release step do not need to be pressurized), the reverse release step and the flushing step, and opens the final charging programmable valves corresponding to the above-mentioned adsorption towers to pressurize them. When their pressure rises to the set value, the corresponding final charging programmable valves are closed until the pressures in all adsorption towers that are in the step requiring pressurization reach or exceed the set value. The control system controls the final charging regulating valve HV101 and all programmable valves to close, and the system automatically stops.

[0040] Wherein, in the step 2, the pressure equalization time of the adsorption tower in the adsorption step and the final charging step, or the adsorption tower in the adsorption step, the first pressure equalization step and the first pressure drop step is 1 minute when the pressure equalization valve is opened for pressure equalization; preferably, in the step 2, the opening of the charging regulating valve is set to 10% when the pressure is opened; more preferably, in the step 3, the set value of the pressure increase of the adsorption tower in the step requiring pressure increase is 0.20MPaG.

[0041] The present invention provides a method for starting an intelligent start-stop pressure swing adsorption hydrogen production system, comprising the following steps:

[0042] Step A, automatic pressure relief: the control system opens the reverse pressure-reducing program-controlled valve corresponding to the adsorption tower that is detected to be in the step of pressure-raising when the pressure swing adsorption hydrogen production system is shut down, opens the adjustable program-controlled valve HV103 to the set opening to start pressure relief, and when the pressure drops to the regeneration pressure, closes the reverse pressure-reducing program-controlled valve, changes the adjustable program-controlled valve HV103 to full opening, and opens the program-controlled valve KV102;

[0043] Step B, automatic pressure increase: After completing the automatic pressure relief step in step A, the control system controls the valve switching of the pressure swing adsorption hydrogen production system to enter normal operation, and at the same time opens the adjustable program-controlled valve HV102 until the pressure in the adsorption tower reaches the pressure of the feed gas;

[0044] Step C, automatic operation: After completing the automatic pressure increase step in step B, open the product gas venting regulating valve PV101 to vent the product gas until the product hydrogen meets the index requirements, close the product gas venting regulating valve PV101, and open the product gas programmable valve on the product gas transmission pipe to output qualified product hydrogen.

[0045] Wherein, in the step A, the opening is set to 15%; preferably, in the step B, when the control system controls the valve switching when the pressure swing adsorption hydrogen production system enters normal operation, the cycle time of the pressure swing adsorption hydrogen production system is maintained at the cycle time at half load; more preferably, in the step B, after opening the adjustable program-controlled valve HV102, the adjustable program-controlled valve HV102 needs to be gradually opened from zero opening to 10% within 30s; further preferably, in the step B, after opening the adjustable program-controlled valve HV102, the raw gas flow rate needs to be controlled at 30% according to the raw gas flowmeter FQ101.

[0046] The purpose of the present invention is to realize intelligent one-button start and stop of the pressure swing adsorption hydrogen production system by improving the existing pressure swing adsorption hydrogen production system. The main method is to respectively set an adjustable program-controlled valve, i.e. a cut-off valve with a regulating function, on the raw gas delivery pipe and the reverse pressure reduction pipe of the pressure swing adsorption hydrogen production system, and add a program-controlled valve on the product gas delivery pipe and the flushing outlet pipe.

[0047] Automatic parking mainly includes the adsorbent regeneration and adsorption tower pressurization process. The specific steps are as follows:

[0048] 1) Adsorbent regeneration

[0049] When the pressure swing adsorption hydrogen production system needs to be stopped, click the one-touch stop button on the control system operation screen, and the control system first closes the adjustable program-controlled valve HV102 on the raw gas transmission pipe and the program-controlled valve KV101 on the product gas external transmission pipe to isolate the pressure swing adsorption system from the raw gas and the product gas, that is, the system no longer enters the raw gas and no longer produces product gas; when running to the first step of the next sub-cycle, the control system marks the adsorption tower that has just entered the adsorption step as numbered "N" (N = the sequence number of the adsorption tower), and the control system automatically changes the sub-cycle time to the time when it is running at half load and continues to run until the adsorption tower numbered "N-1" (if N=1, then define N-1=the maximum number of the adsorption tower) runs to the end of flushing and stops. At this point, all the adsorption towers have been regenerated and no raw gas has been introduced, that is, each adsorption tower is a regenerated "clean" adsorption tower; the adsorption towers are full of hydrogen.

[0050] 2) Adsorption tower pressurization

[0051] After completing the regeneration of the adsorption tower, the control system detects the adsorption tower in the adsorption step and the final filling step (or the first pressure equalization step and the first pressure drop step), marks the above adsorption tower number as "M", opens an equalization valve corresponding to the "M" adsorption tower, and performs pressure equalization. After 1 minute, close the equalization valve corresponding to the "M" adsorption tower; then open the product gas programmable valve corresponding to the "M" tower, and at the same time open the final filling regulating valve, and set the opening of the regulating valve to 10%.

[0052] The control system detects the adsorption towers that are in the step requiring pressure boosting, i.e., the forward release step (if the forward release step has not yet ended, the adsorption tower in the forward release step does not need to relieve pressure, and the corresponding adsorption tower is not marked), the reverse release step, and the flushing step, and marks them as "P". The final filling programmable valve corresponding to the "P" adsorption tower is opened, and the pressure of the low-pressure adsorption tower, i.e., the "P" adsorption tower is boosted. When the pressure of the "P" adsorption tower is greater than or equal to 0.20MPaG, the corresponding final filling programmable valve is closed until the pressure of all "P" adsorption towers reaches 0.20MPaG, and the final filling regulating valve HV101 and all the programmable valves are closed.

[0053] At this point, the pressure of all adsorption towers is above 0.20MPaG, and each adsorption tower is a "clean" adsorption tower, and the pressure swing adsorption system completes the automatic shutdown procedure.

[0054] The automatic start-up of the pressure swing adsorption hydrogen purification system includes three processes: automatic pressure relief, automatic pressure increase, and automatic operation. The specific steps are as follows:

[0055] 1) Automatic pressure relief

[0056] When the pressure swing adsorption hydrogen production system needs to be started, click the one-touch start button on the control system operation screen, and the control system will open the reverse pressure reduction program-controlled valve and adjustable program-controlled valve HV103 corresponding to the "P" adsorption tower, and set the opening of HV103 to 15%; at this time, the "P" adsorption tower begins to release pressure, and when the pressure of the "P" adsorption tower drops to the regeneration pressure, close the reverse pressure reduction program-controlled valve of the "P" adsorption tower until all the reverse pressure reduction program-controlled valves of the "P" adsorption tower are closed, completing the automatic pressure relief of the adsorption tower. The opening of the adjustable program-controlled valve HV103 on the reverse pressure reduction pipe is changed to full open, and the program-controlled valve KV102 on the flushing outlet pipe is opened.

[0057] 2) Automatic voltage boost

[0058] After completing the automatic pressure relief step, the operation of the pressure swing adsorption hydrogen production system is transferred to the valve switching during normal operation, and the system's cycle time remains the cycle time when it is stopped, that is, the cycle time at half load, and at the same time, the adjustable program-controlled valve HV102 on the raw gas delivery pipe is opened, and the adjustable program-controlled valve HV102 gradually opens from zero opening to 10% within 30s, and controls the raw gas flow rate at 30% according to the raw gas flow meter FQ101 on the raw gas delivery pipe. Since the program-controlled valve KV101 on the product gas external transmission pipe is in a closed state and there is no product gas output, as the system operates, the pressure of the adsorption tower in the system in the adsorption state gradually increases until it reaches the pressure of the raw gas.

[0059] 3) Automatic operation

[0060] After completing the automatic pressure increase step, that is, when the pressure in the adsorption tower in the adsorption state reaches the raw gas pressure, open the product gas venting regulating valve PV101 to vent the product gas until the feedback value of the product gas quality online detection instrument R101 reaches the index requirement of the product hydrogen. At this time, close the product gas venting regulating valve PV101, open the programmable valve on the product gas transmission pipe, and the qualified product hydrogen is output to the outside.

[0061] At this point, the control system completes the automatic startup of the pressure swing adsorption hydrogen production system. Thereafter, the operation of the pressure swing adsorption hydrogen production system adjusts the system load and operating parameters as needed.

[0062] In order to enable those skilled in the art to better understand the technical solution of the present invention, the following examples are provided for detailed explanation.

[0063] like Figure 2As shown, it is an 8-tower pressure swing adsorption hydrogen production system with an intelligent start-stop system, the raw gas composition is: H2:N2:CH4=80:4:16, the raw gas pressure is: 2.5MPaG, the product gas pressure is: 2.45MPaG, the product hydrogen purity is 99.9% (mol / mol), the desorption pressure is 0.02MPaG, and the 8-1-4 / P process is adopted, that is, 1 tower adsorption, 4 times pressure equalization, flushing and regeneration process flow, the timing is shown in Table 1.

[0064] There is an adjustable program-controlled valve HV102 on the raw gas transmission pipe, an adjustable program-controlled valve HV103 on the reverse pressure-reducing pipe, a program-controlled valve KV101 on the product gas transmission pipe, a program-controlled valve KV102 on the flushing outlet pipe, a product gas venting regulating valve PV101 on the vent pipeline, a final filling regulating valve HV101 on the final filling pipeline, a raw gas flowmeter FQ101 on the raw gas transmission pipe, and a product gas quality online detection instrument R101 connected to the control system on the product gas transmission pipe.

[0065] The automatic parking process is as follows:

[0066] 1) Adsorption tower regeneration

[0067] When the pressure swing adsorption hydrogen purification system needs to be stopped, click the one-touch stop button on the control system operation screen, and the control system first closes the adjustable program-controlled valve HV102 on the raw gas transmission pipe and the program-controlled valve KV101 on the product gas transmission pipe to isolate the pressure swing adsorption system from the raw gas and product gas, that is, the system no longer enters the raw gas and no longer produces product gas; when running to the first step of the next sub-cycle, this example assumes that it is in the first step of the second sub-cycle, the control system marks the adsorption tower that has just entered the adsorption step as "N" (N = the serial number of the adsorption tower), that is, the second adsorption tower is "N", and at this time adsorption towers 2, 3, and 4 have been completed. Regeneration, no feed gas enters, the gas in the adsorption tower comes from its equalizing gas and the final filling gas, all of which are hydrogen; the control system automatically changes the sub-cycle time to the time when it runs at half load and continues to run until the adsorption tower numbered "N-1" (if N=1, then define N-1=8) runs to the end of the flushing and stops, that is, runs to the end time of the first step of the 6th sub-cycle (this example stops at any time and the adsorption tower regeneration is completed at the end of the first step of the sub-cycle), and all program-controlled valves are closed. At this point, all the adsorption towers have been regenerated and no feed gas has entered, that is, each adsorption tower is a regenerated "clean" adsorption tower; the adsorption towers are all hydrogen.

[0068] 2) Adsorption tower pressurization

[0069] After the regeneration of the adsorption tower is completed, the control system detects the adsorption towers in the adsorption step, the first pressure equalization step and the first pressure equalization step, and marks the adsorption tower number as "M". In this example, towers 5, 6 and 7 are "M" towers; open an equalization valve corresponding to the "M" adsorption tower to equalize the pressure, and close the equalization valve corresponding to the "M" adsorption tower after 1 minute; then open the product gas program-controlled valve corresponding to the "M" tower, and open the final filling regulating valve at the same time, and set the opening of the regulating valve to 10%;

[0070] The control system detects the adsorption tower that needs to be in the step of boosting, i.e., the reverse step and the flushing step (in this example, the forward release is not completed at the end of the first step of any sub-cycle), and marks it as "P". In this example, towers 1 and 2 are "P" towers. The final filling program-controlled valve corresponding to the "P" adsorption tower is opened to boost the pressure of the low-pressure adsorption tower, i.e., the "P" adsorption tower. When the pressure of the "P" adsorption tower is greater than or equal to 0.20MPaG (the judgment basis is |P p -0.20MPa|≤0.02MPa, that is, when the pressure of the "P" adsorption tower reaches 0.20MPa±0.02MPa), close the corresponding final filling program-controlled valve until the pressure of all "P" adsorption towers reaches 0.20MPaG, close the final filling regulating valve HV101 and all program-controlled valves.

[0071] At this point, the pressure of all adsorption towers is above 0.20MPaG, and each adsorption tower is a "clean" adsorption tower, and the pressure swing adsorption system completes the automatic shutdown procedure.

[0072] The automatic startup process is as follows:

[0073] Automatic start includes three processes: automatic pressure relief, automatic pressure increase, and automatic operation. The specific steps are as follows:

[0074] 1) Automatic pressure relief

[0075] When the pressure swing adsorption hydrogen purification system needs to be started, click the one-key start button on the control system operation screen, and the control system will open the reverse pressure reduction program-controlled valve and adjustable program-controlled valve HV103 corresponding to the "P" adsorption tower, and set their opening to 15%; at this time, the "P" adsorption tower begins to release pressure, and when the pressure of the "P" adsorption tower drops to 0.02MPaG (the judgment basis is |P p -0.02MPa|≤0.02MPa, that is, when the pressure of the "P" adsorption tower reaches 0.02MPa±0.02MPa), close the reverse pressure-reducing program-controlled valve of the "P" adsorption tower until all the reverse pressure-reducing program-controlled valves of the "P" adsorption tower are closed, and the adsorption tower is automatically depressurized. The opening of the adjustable program-controlled valve HV103 is changed to full open, and the program-controlled valve KV102 on the flushing outlet pipe is opened.

[0076] 2) Automatic voltage boost

[0077] After completing the automatic pressure relief step, the operation of the pressure swing adsorption hydrogen production system is transferred to the valve switching during normal operation, and the system's cycle time remains the cycle time when it is stopped, that is, the cycle time at half load. At the same time, the adjustable program-controlled valve HV102 on the raw gas transmission pipe is opened, and the program-controlled valve gradually opens from zero opening to 10% within 30s, and the raw gas flow rate is controlled at 30% according to the raw gas flow meter FQ101. Since the program-controlled valve KV101 on the product gas transmission pipe is in a closed state and there is no product gas output, the pressure of the adsorption tower in the adsorption state in the system gradually increases with the operation of the system until it reaches the pressure of the raw gas (the judgment basis is |P A -2.5MPa|≤0.03MPa, that is, the adsorption pressure reaches 2.5MPa±0.03MPa).

[0078] 3) Automatic operation

[0079] After completing the automatic pressurization step, that is, when the pressure in the adsorption tower in the adsorption state reaches the raw gas pressure, open the product gas venting regulating valve PV101 to vent the product gas until the feedback value of the product gas quality online detection instrument R101 meets the index requirement of the product hydrogen. In this example, the hydrogen purity is ≥99.9% (mol / mol). At this time, close the product gas venting regulating valve PV101, open the programmable valve on the product gas transmission pipe, and the qualified product hydrogen is output to the outside.

[0080] At this point, the control system completes the automatic startup of the pressure swing adsorption hydrogen production system. Thereafter, the operation of the pressure swing adsorption hydrogen production system adjusts the system load and operating parameters as needed.

[0081] Table 1: 8-1-4 / P timing table

[0082]

[0083] Note: A: adsorption step, 1D: first pressure drop step, 2D: second pressure drop step, 3D: third pressure drop step, 4D: fourth pressure drop step, PP: forward release step, D: reverse release step, P: flushing step, 4R: fourth pressure increase step, 3R: third pressure increase step, 2R: second pressure increase step, 1R: first pressure increase step, FR: final charging step.

[0084] like Figure 3As shown, a 10-tower pressure swing adsorption hydrogen production system with an automatic start and stop system, raw gas composition: H2:N2:CH4:CO:CO2=72:10:8:2:8, raw gas pressure: 2.5MPaG, product gas pressure: 2.45MPaG, product hydrogen purity 99.9% (mol / mol), CO+CO2≤10ppmv, desorption pressure 0.02MPaG, adopting 10-2-4 / P process, i.e., 2-tower adsorption, 4 times pressure equalization, flushing and regeneration process flow, the timing is shown in Table 2.

[0085] There is an adjustable program-controlled valve HV102 on the raw gas transmission pipe, an adjustable program-controlled valve HV103 on the reverse pressure-reducing pipe, a program-controlled valve KV101 on the product gas transmission pipe, a program-controlled valve KV102 on the flushing outlet pipe, a product gas venting regulating valve PV101 on the vent pipeline, a final filling regulating valve HV101 on the final filling pipeline, a raw gas flowmeter FQ101 on the raw gas transmission pipe, and a product gas quality online detection instrument R101 connected to the control system on the product gas transmission pipe.

[0086] The automatic parking process is as follows:

[0087] 1) Adsorption tower regeneration

[0088] When the pressure swing adsorption hydrogen purification system needs to be stopped, click the one-touch stop button on the control system operation screen. The control system first closes the adjustable programmable valve HV102 on the raw gas transmission pipe and the programmable valve KV101 on the product gas external transmission pipe to isolate the pressure swing adsorption system from the raw gas and product gas, that is, the system no longer enters the raw gas and no longer produces product gas; when running to the first step of the next sub-cycle, this example assumes that it is in the first step of the third sub-cycle, the control system marks the adsorption tower that has just entered the adsorption step as "N" (N = the serial number of the adsorption tower), and the third adsorption tower in this example is "N". At this time, adsorption towers 3, 4, and 5 have completed re- The gas in the adsorption tower comes from the pressure-equalizing gas and the final filling gas, all of which are hydrogen; the control system automatically changes the sub-cycle time to the time when it is running at half load and continues to run until the adsorption tower numbered "N-1" (if N=1, then define N-1=10) runs to the end time of the flushing step and stops, which is the end time of the 1st step of the 9th sub-cycle in this example (the adsorption tower regeneration is completed at the end of the 1st step of the sub-cycle when the vehicle is stopped at any time in this example), and all the program-controlled valves are closed. At this point, all the adsorption towers have been regenerated and no raw gas has been introduced, that is, each adsorption tower is a regenerated "clean" adsorption tower; the adsorption towers are all hydrogen.

[0089] 2) Adsorption tower pressurization

[0090] After the regeneration of the adsorption tower is completed, the control system detects the adsorption towers in the adsorption step, the first pressure equalization step and the first pressure equalization step, and marks the adsorption tower number as "M". In this example, towers 7, 8, 9 and 10 are "M" towers; open an equalization valve corresponding to the "M" adsorption tower to equalize the pressure, and close the equalization valve corresponding to the "M" adsorption tower after 1 minute; then open the product gas program-controlled valve corresponding to the "M" tower, and open the charging pressure regulating valve at the same time, and set the opening of the charging pressure regulating valve to 10%;

[0091] The control system detects the adsorption tower that needs to be in the step of boosting, i.e., the step of reverse release and the step of flushing (in this example, the forward release is not completed at the end of the first step of any sub-cycle), and marks it as "P". In this example, towers 2, 3 and 4 are "P" towers. The final filling program-controlled valve corresponding to the "P" adsorption tower is opened to boost the pressure of the low-pressure adsorption tower, i.e., the "P" adsorption tower. When the pressure of the "P" adsorption tower is greater than or equal to 0.20MPaG (the judgment basis is |P p -0.20MPa|≤0.02MPa (i.e., when the pressure of the "P" adsorption tower reaches 0.20MPa±0.02MPa), close the corresponding final filling program-controlled valve until the pressure of all "P" adsorption towers reaches 0.20MPaG, and then close the final filling regulating valve HV101 and all program-controlled valves.

[0092] At this point, the pressure of all adsorption towers is above 0.20MPaG, and each adsorption tower is a "clean" adsorption tower, and the pressure swing adsorption system completes the automatic shutdown procedure.

[0093] The automatic startup process is as follows:

[0094] Automatic start includes three processes: automatic pressure relief, automatic pressure increase, and automatic operation. The specific steps are as follows:

[0095] 1) Automatic pressure relief

[0096] When the pressure swing adsorption hydrogen production system needs to be started, click the one-key start button on the control system operation screen, the control system will open the reverse pressure reduction program-controlled valve and adjustable program-controlled valve HV103 corresponding to the "P" adsorption tower, and set their opening to 15%; at this time, the "P" adsorption tower begins to release pressure, and when the pressure of "P" drops to 0.02MPaG (the judgment basis is |P p -0.02MPa|≤0.02MPa (i.e., the pressure of the "P" adsorption tower reaches 0.02MPa±0.02MPa), close the reverse pressure-reducing program-controlled valve of the "P" adsorption tower until all the reverse pressure-reducing program-controlled valves of the "P" adsorption tower are closed, and the adsorption tower is automatically depressurized. The opening of the adjustable program-controlled valve HV103 is changed to full open, and the program-controlled valve KV102 on the flushing outlet pipe is opened.

[0097] 2) Automatic voltage boost

[0098] After completing the automatic pressure relief step, the operation of the pressure swing adsorption hydrogen production system is transferred to the valve switching during normal operation, and the system's cycle time remains the cycle time when it is stopped, that is, the cycle time at half load. At the same time, the adjustable program-controlled valve HV102 on the raw gas transmission pipe is opened, and the program-controlled valve gradually opens from zero opening to 10% within 30s, and the raw gas flow rate is controlled at 30% according to the raw gas flow meter FQ101. Since the program-controlled valve KV101 on the product gas transmission pipe is in a closed state and there is no product gas output, the pressure of the adsorption tower in the adsorption state in the system gradually increases with the operation of the system until it reaches the pressure of the raw gas (the judgment basis is |P A -2.5MPa|≤0.03MPa, that is, the adsorption pressure reaches 2.5MPa±0.03MPa).

[0099] 3) Automatic operation

[0100] After completing the automatic pressurization step, that is, when the pressure in the adsorption tower in the adsorption state reaches the raw gas pressure, open the product gas venting regulating valve PV101 to vent the product gas until the feedback value of the product gas quality online detection instrument R101 meets the index requirements of the product hydrogen. In this example, the hydrogen purity is ≥99.9% (mol / mol), CO+CO2≤10ppmv. At this time, close the product gas venting regulating valve PV101, open the programmable valve on the product gas transmission pipe, and the qualified product hydrogen is output to the outside.

[0101] At this point, the control system completes the automatic startup of the pressure swing adsorption hydrogen production system. Thereafter, the operation of the pressure swing adsorption hydrogen production system adjusts the system load and operating parameters as needed.

[0102] Table 2: 10-2-4 / P timing table

[0103]

[0104] Note: A: adsorption step, 1D: first pressure drop step, 2D: second pressure drop step, 3D: third pressure drop step, 4D: fourth pressure drop step, PP: forward release step, D: reverse release step, P: flushing step, 4R: fourth pressure increase step, 3R: third pressure increase step, 2R: second pressure increase step, 1R: first pressure increase step, FR: final charging step.

[0105] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention to illustrate the technical solutions of the present invention, rather than limiting them, and certainly not limiting the patent scope of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. In other words, any changes or modifications made to the main design concept and spirit of the present invention that have no substantive significance, and the technical problems they solve are still consistent with the present invention, should be included in the protection scope of the present invention. In addition, the direct or indirect application of the technical solutions of the present invention in other related technical fields is also included in the patent protection scope of the present invention.

Claims

1. An intelligent start-stop pressure swing adsorption hydrogen production system, comprising a feed gas delivery pipe, an adsorption tower group, a reverse pressure reduction pipe, a flushing outlet pipe, a product gas delivery pipe, a first equalization and final filling program-controlled valve pipeline, a pressure equalization program-controlled valve pipeline, a forward flushing program-controlled valve pipeline, and a control system for controlling the operation of the hydrogen production system, characterized in that: A final filling pipeline is connected between the equalization and final filling program-controlled valve pipelines and the product gas transmission pipeline, and a final filling regulating valve HV101 is arranged on the final filling pipeline. A venting pipeline is connected to the product gas transmission pipeline, and a product gas venting regulating valve PV101 is arranged on the venting pipeline. An adjustable program-controlled valve HV102 is arranged on the raw gas transmission pipeline, an adjustable program-controlled valve HV103 is arranged on the reverse pressure reduction pipe, a program-controlled valve KV102 is arranged on the flushing outlet pipe, and a program-controlled valve KV101 is arranged on the product gas transmission pipeline; The control system is respectively connected to the final filling regulating valve HV101, the product gas venting regulating valve PV101, the adjustable program-controlled valve HV102, the adjustable program-controlled valve HV103, the program-controlled valve KV102 and the program-controlled valve KV101; The adsorption tower group is provided with a pressure detection instrument for detecting the pressure inside the adsorption tower; The raw gas delivery pipe is equipped with a raw gas flow meter FQ101 connected to the control system; A product gas program-controlled valve connected to the control system is provided between the product gas transmission pipe and the adsorption tower group; a raw gas program-controlled valve connected to the control system is provided between the raw gas transmission pipe and the adsorption tower group; A reverse pressure reduction program-controlled valve pipeline is provided between the adsorption tower group and the reverse pressure reduction pipe; a flushing outlet program-controlled valve pipeline is provided between the adsorption tower group and the flushing outlet pipe; and a product gas quality online detection instrument R101 connected to the control system is provided on the product gas transmission pipeline.

2. According to claim 1, a parking method for an intelligent start-stop pressure swing adsorption hydrogen production system is characterized in that: The following steps are involved: Step 1, adsorbent regeneration: the control system first controls the adjustable program-controlled valve HV102 and the program-controlled valve KV101 to close, and then changes the next sub-cycle time to the time when the half-load operation is continued to run until each adsorption tower in the adsorption tower group is flushed and stops; Step 2, pressure equalization of the adsorption tower group: after the adsorption tower group completes the regeneration of the adsorption tower, the control system detects the adsorption tower in the adsorption step and the final filling step, or detects the adsorption tower in the adsorption step, the first pressure equalization step and the first pressure equalization step, and opens an equalization valve corresponding to the adsorption tower in the above steps for pressure equalization. After the pressure equalization is completed, the corresponding equalization valve is closed and the product gas program-controlled valve and the final filling regulating valve corresponding to the adsorption tower in the above steps are opened; Step 3, pressurizing the adsorption tower group: the control system detects the adsorption towers that are in the steps requiring pressure boosting, i.e., the forward release step, the reverse release step and the flushing step, and opens the final charging program-controlled valves corresponding to the above-mentioned adsorption towers to boost their pressure. When their pressure rises to the set value, the corresponding final charging program-controlled valves are closed until the pressures in all the adsorption towers that are in the steps requiring pressure boosting reach or exceed the set value. The control system controls the final charging regulating valve HV101 and all the program-controlled valves to close, and the system automatically stops.

3. The parking method according to claim 2, characterized in that: In the step 2, the pressure equalization time of the adsorption tower in the adsorption step and the final charging step, or the adsorption tower in the adsorption step, the first pressure equalization step and the first pressure drop step is 1 minute when the pressure equalization valve is opened for pressure equalization; in the step 2, the opening of the charging regulating valve is set to 10% when the pressure is opened; in the step 3, the set value of the pressure increase of the adsorption tower in the forward release step, the reverse release step or the flushing step is 0.20MPaG; if the forward release step has not been completed, the adsorption tower in the forward release step does not need to be pressurized.

4. According to claim 1, a method for starting an intelligent start-stop pressure swing adsorption hydrogen production system is characterized in that: The following steps are involved: Step A, automatic pressure relief: the control system opens the reverse pressure-reducing program-controlled valve corresponding to the adsorption tower that is detected to be in the step of pressure-raising when the pressure swing adsorption hydrogen production system is shut down, opens the adjustable program-controlled valve HV103 to the set opening to start pressure relief, and when the pressure drops to the regeneration pressure, closes the reverse pressure-reducing program-controlled valve, changes the adjustable program-controlled valve HV103 to full opening, and opens the program-controlled valve KV102; Step B, automatic pressure increase: After completing the automatic pressure relief step in step A, the control system controls the valve switching of the pressure swing adsorption hydrogen production system to enter normal operation, and at the same time opens the adjustable program-controlled valve HV102 until the pressure in the adsorption tower reaches the pressure of the feed gas; Step C, automatic operation: After completing the automatic pressure increase step in step B, open the product gas venting regulating valve PV101 to vent the product gas until the product hydrogen meets the index requirements, close the product gas venting regulating valve PV101, and open the product gas programmable valve on the product gas transmission pipe to output qualified product hydrogen.

5. The startup method according to claim 4, characterized in that: In step A, the opening is set to 15%; in step B, when the control system controls the valve switching when the pressure swing adsorption hydrogen production system enters normal operation, the cycle time of the pressure swing adsorption hydrogen production system remains the cycle time at half load; in step B, after opening the adjustable program-controlled valve HV102, the adjustable program-controlled valve HV102 needs to be gradually opened from zero opening to 10% within 30 seconds; in step B, after opening the adjustable program-controlled valve HV102, the raw gas flow rate needs to be controlled at 30% according to the raw gas flow meter FQ101.

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