Cleaning device and method for cleaning reaction tube in organic liquid hydrogen storage system

Abstract

The invention provides a cleaning device and method for cleaning a reaction tube in an organic liquid hydrogen storage system, and belongs to the technical field of hydrogen energy storage device cleaning. The cleaning device comprises: a heating tank for accommodating and heating a reaction tube; the brush is used for cleaning the inner wall of the reaction tube; the cleaning liquid storage tank is provided with a liquid inlet and a liquid outlet, and the liquid inlet and the liquid outlet are both communicated with the heating tank; the hydraulic machine is arranged between the liquid inlet and the reaction tube. The reaction tube is placed in the heating tank, and the cleaning fluid pressurized by the hydraulic machine is conveyed into the heating tank through the cleaning fluid storage tank, so that the reaction tube can be cleaned by the cleaning fluid under a certain heating condition and a certain pressure, and meanwhile, the inner wall of the reaction tube is cleaned by a brush, so that the reaction tube can be fully cleaned; and the device is suitable for small reaction tubes with various specifications in an organic liquid hydrogen storage system.

Description

Technical Field

[0001] The present invention relates to the technical field of cleaning hydrogen energy storage devices, and in particular to a cleaning device and method for cleaning a reaction tube in an organic liquid hydrogen storage system. Background Art

[0002] Hydrogen energy is an important part of the future energy system, an important carrier for energy users to achieve green and low-carbon transformation, and a key development direction for strategic emerging industries and future industries. Storage and transportation is a link in the hydrogen energy industry. Compared with high-pressure tank gas storage and transportation, the advantage of organic liquid hydrogen carrier (LOHC) is that it does not require pressure vessels and is safe and convenient to transport. It is the direction for realizing large-scale hydrogen energy storage and transportation in the future.

[0003] As one of the organic liquid hydrogen carriers, N-ethylcarbazole has stable performance and high safety after hydrogenation of organic hydride. It can be stored at room temperature and pressure. The storage method is similar to that of petroleum. It has high hydrogen storage density, which can reach 5.6% / wt in theory. In the research and testing stage, N-ethylcarbazole, as a hydrogen carrier, will be subjected to dehydrogenation reaction in the reaction tube filled with catalyst. After repeated cycle experiments, N-ethylcarbazole itself has a high melting point, strong viscosity, and is easy to solidify at room temperature. It often adheres to the inner cavity of the reaction tube, causing the subsequent catalyst loading to gradually decrease, reducing the porosity of the inner cavity, and easily causing blockage and damage to the reaction tube, which ultimately affects the hydrogen storage performance and efficiency. Therefore, it is necessary to clean the reaction tube in stages. The existing cleaning equipment is difficult to match with small reaction tubes with various specifications. In addition, in view of the high viscosity and easy solidification properties of N-ethylcarbazole, the cleaning agent needs to meet excellent compatibility and reduce the viscosity and melting point of the mixed liquid after mixing. Summary of the invention

[0004] The present application provides a cleaning device and method for cleaning reaction tubes in an organic liquid hydrogen storage system, so as to solve the problem that existing cleaning equipment cannot match small reaction tubes of various specifications in the organic liquid hydrogen storage system.

[0005] The embodiment of the present application provides a cleaning device for cleaning a reaction tube in an organic liquid hydrogen storage system, which comprises: A heating tank, used for accommodating and heating the reaction tube; A brush, used for cleaning the inner wall of the reaction tube; A cleaning liquid storage tank, having a liquid inlet and a liquid outlet, wherein the liquid inlet and the liquid outlet are both connected to the heating tank; The hydraulic press is arranged between the liquid inlet and the reaction tube.

[0006] The beneficial effect of the above technical solution adopted in the present application is: by placing the reaction tube in a heating tank, and conveying the cleaning liquid pressurized by a hydraulic press into the heating tank from the cleaning liquid storage tank, the reaction tube can be cleaned by the cleaning liquid under certain heating conditions and a certain pressure, and at the same time, a brush is used to clean the inner wall of the reaction tube, so that the reaction tube can be fully cleaned, and it is suitable for small reaction tubes of various specifications in the organic liquid hydrogen storage system.

[0007] Based on the above technical solution, the present application can also be improved as follows: Furthermore, the extension direction of the heating tank and the extension direction of the reaction tube are both vertical directions, and the liquid inlet and the liquid outlet are respectively connected to two ends of the extension direction of the heating tank.

[0008] The beneficial effect of the above technical solution adopted in the present application is that by setting the extension direction of the heating tank and the extension direction of the reaction tube to a vertical direction, the cleaning liquid can better contact and clean the reaction tube.

[0009] Furthermore, a liquid inlet valve is provided on the pipeline between the liquid inlet and the heating tank, and a liquid outlet valve is provided on the pipeline between the liquid outlet and the heating tank.

[0010] Furthermore, both ends of the heating tank in the extension direction are respectively connected with an air inlet pipe and an air outlet pipe, the air inlet pipe is provided with an air inlet valve, and the air outlet pipe is provided with an air outlet valve.

[0011] The beneficial effect of the above technical solution adopted in the present application is that by setting the air inlet pipe and the air outlet pipe, the reaction tube can be further purged with gas, thereby better achieving the cleaning of the reaction tube.

[0012] Further, the brush is connected to a motor, and the motor can drive the brush to rotate in the reaction tube; and / or The surface of the heating tank is provided with a heat-insulating component; and / or The cleaning device also includes a bracket, the bracket is provided with a slot, and the heating slot is clamped in the slot.

[0013] The beneficial effects of the above technical solution adopted in the present application are: by setting a motor, the reaction tube can be automatically cleaned. By setting a heat preservation component, the heating tank can be kept warm.

[0014] Furthermore, the cleaning device also includes a controller, which is communicatively connected with the heating tank, the liquid inlet valve, the liquid outlet valve, the air inlet valve, the air outlet valve and the motor.

[0015] The beneficial effect of the above technical solution adopted in the present application is: by setting a controller, the heating tank, liquid inlet valve, liquid outlet valve, air inlet valve, air outlet valve and motor can be controlled by the controller, so as to better realize the control of the reaction tube cleaning process.

[0016] The present application also provides a method for cleaning a reaction tube in an organic liquid hydrogen storage system, comprising the following steps: The reaction tube is cleaned with a cleaning liquid, and then purged with an inert gas.

[0017] Furthermore, the cleaning liquid is ethylcyclohexane.

[0018] The beneficial effect of the above technical solution adopted in the present application is that ethylcyclohexane has excellent solubility for N-ethylcarbazole remaining in the reaction tube, and at the same time has low chemical toxicity, good chemical stability, and a boiling point of 130°C-132°C. After mixing with N-ethylcarbazole, it can reduce the viscosity and melting point of the mixed solution, thereby achieving a better effect of cleaning the reaction tube.

[0019] Further, the temperature of the cleaning liquid is 50-150° C., the cleaning pressure of the cleaning liquid is 4-8 MPa, and the cleaning time is 0.5-2 h; and / or The cleaning process further includes: brushing the inner wall of the reaction tube with a brush, the rotation speed of the brush being 500-1000 r / min; and / or The pressure of the inert gas is 0.1-0.2 MPa, the temperature of the inert gas is 50-150° C., and the purging time is 0.1-1 h; and / or The purging process further includes: brushing the inner wall of the reaction tube with a brush, and the rotation speed of the brush is 500-1000r / min. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 A schematic diagram of the structure of a cleaning device for cleaning a reaction tube in an organic liquid hydrogen storage system provided in an embodiment of the present application; Figure 2is the chromatogram of S1 provided in Example 1 of the present application; Figure 3 is the chromatogram of D1 provided in Comparative Example 1 of the present application; Among them, 1-insulation component; 2-heating tank; 3-reaction tube; 4-connecting rod; 5-brush; 6-liquid inlet valve; 7-liquid outlet valve; 8-card slot; 9-controller; 10-bracket; 11-hydraulic press; 12-cleaning liquid storage tank; 13-motor; 14-inlet valve; 15-outlet valve. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0024] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually measured according to national standards. If there is no corresponding national standard, then proceed according to general international standards, conventional conditions, or according to the conditions recommended by the manufacturer. Example

[0025] like Figure 1 As shown, this embodiment provides a cleaning device and method for cleaning a reaction tube in an organic liquid hydrogen storage system, comprising the following steps: (1) Assembly of the cleaning device: The surface of the heating tank 2 is covered with a heat-insulating component 1, which is a heat-insulating plate. The bottom of the heating tank 2 is clamped with the clamping groove 8 on the bracket 10, so that the heating tank 2 is fixed on the bracket 10, and the heating tank 2 is extended in the vertical direction. The outlet of the cleaning liquid storage tank 12, the hydraulic pressure 11, and the bottom of the heating tank 2 are connected in sequence through a pipeline, and the top of the heating tank 2 is connected with the liquid inlet of the cleaning liquid storage tank 12. At the same time, the bottom and top of the heating tank in the extension direction are also connected with air inlet 11 and air inlet 11 respectively. The liquid inlet valve 6, the liquid outlet valve 7, the air inlet valve 14, and the air outlet valve 15 are respectively installed on the pipeline between the liquid inlet of the cleaning liquid storage tank 12 and the heating tank 2, the pipeline between the liquid outlet of the cleaning liquid storage tank 12 and the heating tank 2, the air inlet pipe, and the air outlet pipe. The reaction tube 3 to be cleaned is placed in the heating tank 2, and the inlet and outlet of the reaction tube 3 are arranged in the vertical direction. The brush 5 is placed in the reaction tube 3 and connected to the motor 13 through the connecting rod 4. The lid is covered and tightened to seal the reaction tube 3; (2) First cleaning: Pour 300 mL of ethylcyclohexane into the cleaning liquid storage tank 12, open the liquid inlet valve 6 and the liquid outlet valve 7, close the air inlet valve 14 and the air outlet valve 15, then set the hydraulic pressure of the hydraulic press 11 to 4 MPa, the heating temperature of the heating tank 2 to 60°C, the heating time to 0.5 h, and the speed of the brush 5 to 500 r / min on the controller 9, so that the ethylcyclohexane circulates in the liquid pipeline and cleans for 0.5 h. After the cleaning is completed, close the liquid outlet at the bottom of the cleaning liquid storage tank 12, wait for the refluxed ethylcyclohexane to return to the cleaning liquid storage tank 12, close the hydraulic press 11 and the brush 5, pour out the ethylcyclohexane in the cleaning liquid storage tank 12, and replace it with a new 300 ml of ethylcyclohexane in the cleaning liquid storage tank 12; (3) Second washing: repeat the first washing process, perform a second washing, and then collect the ethylcyclohexane after the second washing; (4) Purging: Open the liquid inlet valve 6 and the liquid outlet valve 7, the air inlet valve 14 and the air outlet valve 5, and introduce nitrogen through the air inlet pipe. The gas pressure is 0.1 MPa and the ventilation time is 0.5 h. At the same time, the heating temperature of the heating tank on the controller 9 is set to 150°C and the speed of the brush 5 is 500 r / min. After the ventilation and purging is completed, close all circuits and valve switches. After the heater cools to room temperature, take out the reaction tube and complete the cleaning. Example

[0026] This embodiment is basically the same as Embodiment 1, except that in the first cleaning and second cleaning processes in this embodiment, the hydraulic pressure is 6 MPa and the heating temperature is 80°C. Example

[0027] This embodiment is basically the same as Embodiment 1, except that in this embodiment, during the first cleaning and the second cleaning process, the hydraulic pressure is 8 MPa and the heating temperature is 100°C. Example

[0028] This embodiment is basically the same as embodiment 1, the only difference being that in the first cleaning and second cleaning processes in this embodiment, the hydraulic pressure is 4 MPa and the heating temperature is 120°C.

[0029] Comparative Example 1: This comparative example is substantially the same as Example 1, except that ethylcyclohexane is replaced with anhydrous ethanol in this comparative example.

[0030] Comparative Example 2: This comparative example is basically the same as Example 1, with the only difference being that in the first cleaning and second cleaning processes in this comparative example, the hydraulic pressure is 4 MPa, and the heating function of the heating tank 2 is turned off.

[0031] Comparative Example 3: This comparative example is basically the same as Example 1, except that in the first cleaning and second cleaning processes in this comparative example, the hydraulic pressure is 4 MPa and the heating temperature is 150°C.

[0032] Test Example: The ethylcyclohexane after the second washing in the embodiment and the comparative example was collected and named S1, S2, S3, S4, D1, D2, and D3, respectively, and chromatographic test analysis was performed on them. The results are shown in Table 1.

[0033] Table 1 Comparison of the purity of substances after different cleaning methods in the embodiments and comparative examples

[0034] As can be seen from Table 1, in Examples 1-4, ethylcyclohexane is used as the cleaning liquid, the heating temperature is 60°C-120°C, the hydraulic pressure is 4-8Mpa, and after cleaning for 1.0h, the collected liquid has a purity of more than 99.0%. Compared with Comparative Example 1, anhydrous ethanol is used, which has a purity of only about 83.31%, and has a very obvious cleaning effect. For Comparative Example 2, the purity is 98.47%, which is slightly lower, and for Comparative Example 3, the purity is 95.55%, which is a large decrease. Since the boiling point and solubility of anhydrous ethanol are lower than those of ethylcyclohexane, it is not as good as ethylcyclohexane in cleaning; in the appropriate temperature range, the solubility of ethylcyclohexane is fully utilized, and the cleaning effect is greatly improved, while if the temperature is too high, ethylcyclohexane will volatilize, reducing the cleaning effect.

[0035] Table 2 shows the test data obtained by using ethylcyclohexane as the cleaning liquid after secondary cleaning provided in Example 1 of the present application, and the collected liquid S1 is tested by a chromatograph. Figure 2 Table 3 is the chromatogram of S1 provided in Example 1 of the present application. Table 3 is the test data obtained by testing the collected liquid D1 by chromatograph after secondary cleaning using anhydrous ethanol as the cleaning liquid provided in Comparative Example 1 of the present application. Figure 3 It is the chromatogram of D1 provided in Comparative Example 1 of the present application.

[0036] Table 2

[0037] Table 3

[0038] In Table 2 and Table 3, retention time refers to the time from injection to arrival of the peak of the substance. Peak area is the peak area of ​​the substance, which can represent the relative content of the substance. Peak height indicates the peak height. Area percentage refers to the area ratio between each peak, which is also the purity between each substance. In the S1 chromatogram of Table 2, the peak with the largest peak height is ethylcyclohexane, and in the D1 chromatogram of Table 3, the peak with the largest peak height is anhydrous ethanol, and the remaining peaks are all residues. As can be seen from Table 2 and Table 3, this application uses ethylcyclohexane to clean the reaction tube at a suitable temperature to remove most of the residues, so that the purity in the tube reaches more than 99%.

[0039] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A cleaning device for cleaning a reaction tube in an organic liquid hydrogen storage system, characterized in that: include: A heating tank, used for accommodating and heating the reaction tube; A brush, used for cleaning the inner wall of the reaction tube; A cleaning liquid storage tank, having a liquid inlet and a liquid outlet, wherein the liquid inlet and the liquid outlet are both connected to the heating tank; The hydraulic press is arranged between the liquid inlet and the reaction tube.

2. The cleaning device for cleaning the reaction tube in the organic liquid hydrogen storage system according to claim 1, characterized in that: The extension direction of the heating tank and the extension direction of the reaction tube are both vertical directions, and the liquid inlet and the liquid outlet are respectively connected to two ends of the extension direction of the heating tank.

3. The cleaning device for cleaning the reaction tube in the organic liquid hydrogen storage system according to claim 2, characterized in that: A liquid inlet valve is arranged on the pipeline between the liquid inlet and the heating tank, and a liquid outlet valve is arranged on the pipeline between the liquid outlet and the heating tank.

4. The cleaning device for cleaning the reaction tube in the organic liquid hydrogen storage system according to claim 3, characterized in that: The two ends of the heating tank in the extension direction are also connected with an air inlet pipe and an air outlet pipe respectively. The air inlet pipe is provided with an air inlet valve, and the air outlet pipe is provided with an air outlet valve.

5. The cleaning device for cleaning the reaction tube in the organic liquid hydrogen storage system according to claim 4, characterized in that: The brush is connected to a motor, and the motor can drive the brush to rotate in the reaction tube; and / or The surface of the heating tank is provided with a heat-insulating component; and / or The cleaning device also includes a bracket, the bracket is provided with a slot, and the heating slot is clamped in the slot.

6. The cleaning device for cleaning the reaction tube in the organic liquid hydrogen storage system according to claim 5, characterized in that: The cleaning device also includes a controller, which is communicatively connected with the heating tank, the liquid inlet valve, the liquid outlet valve, the air inlet valve, the air outlet valve and the motor.

7. A method for cleaning a reaction tube in an organic liquid hydrogen storage system, characterized in that: The following steps are involved: The reaction tube is cleaned with a cleaning liquid, and then purged with an inert gas.

8. The method for cleaning the reaction tube in the organic liquid hydrogen storage system according to claim 7, characterized in that: The cleaning liquid is ethylcyclohexane.

9. The method for cleaning the reaction tube in the organic liquid hydrogen storage system according to claim 7, characterized in that: The temperature of the cleaning liquid is 50-150° C., the cleaning pressure of the cleaning liquid is 4-8 MPa, and the cleaning time is 0.5-2 h; and / or The cleaning process further includes: brushing the inner wall of the reaction tube with a brush, the rotation speed of the brush being 500-1000 r / min; and / or The pressure of the inert gas is 0.1-0.2 MPa, the temperature of the inert gas is 50-150° C., and the purging time is 0.1-1 h; and / or The purging process further includes: brushing the inner wall of the reaction tube with a brush, and the rotation speed of the brush is 500-1000r / min.

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