Filling system of cryogenic propellant and improvement method

Abstract

The invention relates to the technical field of low-temperature propellant filling, and particularly discloses a low-temperature propellant filling system which comprises a filling pipeline, and the tail end of the filling pipeline is mounted at a storage tank filling port; the filling pipeline is communicated with the low-temperature storage tank through the storage tank filling port, and a first valve is mounted on the filling pipeline; the drainage assembly comprises a drainage pipe, the initial end of the drainage pipe is installed between the first valve of the filling pipeline and the storage tank filling port, a collecting pipe is arranged at the tail end of the drainage pipe, and a second valve is arranged on the drainage pipe; the discharging assembly is additionally arranged on the filling pipeline, redundant low-temperature propellants in the low-temperature storage box are matched, in the equipment parking process, the redundant low-temperature propellants in the redundant part in the low-temperature storage box are discharged through drainage, bubbles generated by heat leakage are discharged out of a pipeline system in time, the situation that bubbles are gathered to form a bubbling spring is prevented, and generation of the bubbling spring is eradicated.

Description

Technical Field

[0001] The invention relates to the technical field of cryogenic propellant filling, and in particular to a cryogenic propellant filling system. Background Art

[0002] In vertical pipelines with large aspect ratios, such as filling pipelines for equipment that requires cryogenic propellants to operate, cryogenic propellants will evaporate and produce bubbles due to heat leakage in pipelines under low temperature and low heat flow conditions. As the evaporation volume gradually increases, the static pressure in the vertical pipeline decreases, and bubble generation accelerates, quickly forming a large number of bubbles that block the pipeline. After accumulating for a period of time, large bubbles will rapidly "take out" the liquid column above the pipeline. The liquid column is displaced by the released vapor and finally breaks. Subsequently, the liquid above the vertical pipeline refills the pipeline, causing water hammer and pressure fluctuations. The system returns to the underheated boiling condition, resulting in repeated ejection of air or liquid flow. This phenomenon is called the spring phenomenon. The spring phenomenon is rooted in heat leakage in the cryogenic pipeline and develops in vertical pipelines with large aspect ratios. In order to prevent the bubbles generated by the spring phenomenon from affecting other areas and equipment, it needs to be treated;

[0003] In the prior art, the liquid oxygen pressurization and delivery system of the Hercules 1 and Saturn 5 in the United States adopts a helium injection and blowing scheme; after the helium is injected and blown at the oxygen plus connector, the flow rate is about 0.566m / s. The mechanism is: during the blowing process, the oxygen partial pressure in the nitrogen bubble is 0, forming a vapor pressure difference with the liquid oxygen, causing the hot oxygen to evaporate and diffuse like helium to form a cooling effect, which can absorb the evaporation heat and inhibit the source of the spring. Disadvantages: The discharge of the blowing gas in the pipeline and the tank and the disturbance of the steam to the liquid bring about flow uncertainty. Helium is redundant for the oxygen system, and the amount of helium used is large and wasteful.

[0004] In summary, a new solution is urgently needed to address the gushing phenomenon in cryogenic propellant filling systems. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a filling system for cryogenic propellant.

[0006] A filling system for cryogenic propellant comprises a filling pipeline, the end of which is installed at a tank filling port; the filling pipeline is connected to a cryogenic tank through the tank filling port, and a first valve is installed on the filling pipeline;

[0007] A discharge assembly, the discharge assembly comprising a discharge pipe, the beginning of the discharge pipe being installed between the first valve of the filling pipeline and the filling port of the tank, the end of the discharge pipe being provided with a collecting pipe, and the discharge pipe being provided with a second valve;

[0008] The cryogenic tank is provided with redundancy according to the volume of cryogenic propellant required for use, and the cryogenic tank is filled up through a filling pipeline to fill the redundant part.

[0009] The pipe of the drainage pipe is DN40, and a temperature sensor and a pressure sensor are installed on the drainage pipe.

[0010] The discharge pipe is also provided with a third valve which is a regulating valve, and the second valve is a stop valve.

[0011] The filling pipeline is a DN150 pipeline, and the collecting pipe is DN350.

[0012] An improved method for a cryogenic propellant filling system includes a filling pipeline, the end of which is installed at a tank filling port, the filling pipeline is connected to a cryogenic tank through the tank filling port, and a first valve is installed on the filling pipeline;

[0013] A fourth valve is also installed on the filling pipeline, and the fourth valve is located on the side of the first valve away from the low-temperature storage tank. A discharge pipeline is provided between the first valve and the second valve, and the discharge pipeline is connected to a collecting pipe, and a fifth valve is provided on the discharge pipeline;

[0014] A discharge pipe is installed and connected between the first valve and the tank filling port, and a second valve is arranged on the discharge pipe.

[0015] The filling pipeline and the discharge pipeline are DN150 pipelines, the collecting pipe is DN350, the pipeline of the discharge pipe is DN40, and a temperature sensor and a pressure sensor are installed on the discharge pipe.

[0016] The discharge pipe is also provided with a third valve which is a regulating valve, and the second valve is a stop valve.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention adds a discharge component to the filling pipeline, cooperates with the excess cryogenic propellant in the cryogenic tank, and discharges the redundant cryogenic propellant in the cryogenic tank through drainage during the parking of the equipment, so that the bubbles generated by the heat leakage are discharged from the pipeline system in time. At the same time, the bubbles are discharged along with the cryogenic propellant to reduce the temperature of the heat leakage part of the pipeline, delay the generation of new bubbles, prevent them from gathering to form springs, and thus prevent the generation of springs.

[0019] 2. The present invention aims to solve the problem that the existing filling system cannot eliminate the bubbles generated by heat leakage, and bubbles may gather to form a spring; according to the principle of minimum modification, a discharge pipe connected to DN40 is installed between the first valve and the tank filling port, so that the bubbles generated by heat leakage can be discharged from the pipeline system in time to prevent them from gathering to form a spring, thereby eliminating the pressure fluctuation caused by the spring and preventing the low-temperature tank from being discharged too quickly to cause decompression. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0021] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0022] Figure 2 It is a structural diagram of embodiment 2 of the present invention.

[0023] In the figure: 1, filling pipeline; 2, first valve; 3, discharge pipe; 4, second valve; 5, third valve; 6, collecting pipe; 7, fourth valve; 8, discharge pipeline; 9, fifth valve; 10, low-temperature storage tank. DETAILED DESCRIPTION

[0024] The following will disclose multiple embodiments of the present invention with drawings. For the purpose of clear description, many physical details will be described together in the following description. However, it should be understood that these physical details should not be used to limit the present invention. That is, in some embodiments of the present invention, these physical details are not necessary. In addition, for the purpose of simplifying the drawings, some conventional structures and components will be depicted in a simple schematic manner in the drawings.

[0025] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0026] Embodiment 1

[0027] See also Figure 1The cryogenic propellant filling system of the present invention, as a newly built filling system for cryogenic propellant, comprises a filling pipeline 1, the end of which is installed at the tank filling port, the filling pipeline 1 is connected with the cryogenic tank 10 through the tank filling port, the filling pipeline 1 is installed with a first valve 2, and also comprises a drainage component, the drainage component comprises a drainage pipe 3, the starting end of the drainage pipe 3 is installed between the first valve 2 of the filling pipeline 1 and the tank filling port, the end of the drainage pipe 3 is provided with a collecting pipe 6, and the drainage pipe 3 is provided with a second valve 4;

[0028] The cryogenic tank 10 is provided with redundancy according to the volume of cryogenic propellant required for use, and the cryogenic tank 10 is filled up through the filling pipeline 1 and the redundant part is filled.

[0029] The pipe of the discharge pipe 3 is DN40, and a temperature sensor and a pressure sensor are installed on the discharge pipe 3.

[0030] The discharge pipe 3 is also provided with a third valve 5 which is a regulating valve, and the first valve 2 and the second valve 4 are both stop valves; by closing the third valve 5, opening the second valve 4 and then step-adjusting the opening of the third valve 5, the filling pipeline 1 can be effectively precooled with a small flow rate.

[0031] The filling pipe 1 is a DN150 pipe and the collecting pipe 6 is a DN350 pipe.

[0032] When using the present invention:

[0033] The cryogenic propellant in the cryogenic storage tank 10 is discharged in a periodic or continuous manner to discharge the redundant cryogenic propellant, so that the bubbles generated by the heat leakage are discharged from the pipeline system in time. At the same time, the bubbles discharged along with the cryogenic propellant can reduce the temperature of the heat leakage part of the pipeline, delay the generation of new bubbles, and prevent them from gathering to form a spring, thereby eliminating the generation of a spring.

[0034] When the cryogenic storage tank 10 is automatically filled with cryogenic propellant or supplemented with cryogenic propellant before launch, since the cryogenic propellant in the filling pipeline 1 is in a flowing state, it will not cause heat leakage accumulation, and thus no spring will appear;

[0035] When the cryogenic propellant required by the cryogenic storage tank 10 is filled to the required level, the cryogenic propellant is continuously added to fill the redundant part of the cryogenic storage tank 10 to ensure that there is excess cryogenic propellant in the cryogenic storage tank 10 to discharge bubbles, and then the first valve 2 on the filling pipeline 1 is closed. When the first valve 2 on the filling pipeline 1 is closed, the cryogenic propellant is in a stagnant state, and heat leakage will gradually occur. In order to prevent the bubbles generated by the heat leakage from gathering to form a spring, the second valve 4 located in the discharge pipe 3 is opened, so that the cryogenic propellant located in the cryogenic storage tank 10 is discharged in the reverse direction, thereby preventing the occurrence of pipe bursts by installing a discharge assembly on the filling pipeline 1.

[0036] Since the generation and aggregation of bubbles requires a certain amount of time, the second valve 4 located on the discharge pipe 3 can determine the opening and closing time according to the heat leakage situation;

[0037] According to the equipment parking time, the redundant volume of the cryogenic tank 10, and the discharge flow of the drainage component, a certain amount of propellant needs to be added on the basis of the normal usage to meet the cryogenic propellant discharge demand during the equipment parking stage. During the actual discharge process, if the reserved cryogenic propellant residue does not match the maximum actual discharge rate of the drainage component, the valve opening can be adjusted in real time according to the discharge rate; when the discharge flow is too large and it is estimated that the cryogenic propellant residue is obviously insufficient after continuous discharge, the opening of the third valve 5 is reduced to reduce the discharge flow; when the discharge flow is too small and it is estimated that the cryogenic propellant residue is obviously large after continuous discharge, the opening of the third valve 5 is increased to increase the discharge flow.

[0038] Discharge method: close the third valve 5 and open the second valve 4; adjust the opening of the third valve 5 in steps, first pre-cool the filling pipeline 1 with a small flow rate, and after pre-cooling, continue to adjust the opening of the third valve 5 until the discharge flow requirement is met.

[0039] Discharge mode: Continuous discharge is possible, and the discharge rate is preset according to the capacity of the redundant cryogenic propellant in the cryogenic tank 10. It takes a certain period of time for the actual discharge flow heat leakage to form a spring during the process. Therefore, intermittent discharge is also possible, and the discharge interval is determined according to the amount of heat leakage and the remaining amount of cryogenic propellant.

[0040] Embodiment 2:

[0041] See also Figure 2 , an improved method for a filling system of a cryogenic propellant, comprising a filling pipeline 1, the end of which is installed at a tank filling port, the filling pipeline 1 is connected to a cryogenic tank 10 through the tank filling port, and a first valve 2 is installed on the filling pipeline 1;

[0042] A fourth valve 7 is also installed on the filling pipeline 1. The fourth valve 7 is located on the side of the first valve 2 away from the low-temperature storage tank 10. A discharge pipeline 8 is provided between the first valve 2 and the second valve 4. The discharge pipeline 8 is connected to a collecting pipe 6, and a fifth valve 9 is provided on the discharge pipeline 8.

[0043] The cryogenic tank 10 is provided with redundancy according to the volume of cryogenic propellant required for use, and the cryogenic tank 10 is filled up through the filling pipeline 1 and the redundant part is filled;

[0044] A discharge pipe 3 is installed and connected between the first valve 2 and the tank filling port, and a second valve 4 is provided on the discharge pipe 3;

[0045] The filling pipe 1 and the discharge pipe 8 are DN150 pipes, the collecting pipe 6 is DN350, the pipe of the discharge pipe 3 is DN40, and the temperature sensor and the pressure sensor are installed on the discharge pipe 3;

[0046] The discharge pipe 3 is also provided with a third valve 5 which is a regulating valve, and the first, second, fourth and fifth valves 9 are all stop valves;

[0047] In this example:

[0048] As an improvement method for the filling system of cryogenic propellant, in order to solve the problem that the existing filling system cannot eliminate the bubbles generated by heat leakage, and bubbles may gather to form springs. According to the principle of minimum modification, a DN40 discharge pipe 3 can be installed between the first valve 2 and the tank filling port, and a third valve 5 as a regulating valve and a second valve 4 as a stop valve can be set on the discharge pipe 3. Through the DN40 discharge pipe 3, the cryogenic propellant is discharged regularly or continuously, so that the bubbles generated by heat leakage are discharged from the pipeline system in time, and the bubbles are prevented from gathering to form springs, thereby eliminating the pressure fluctuation caused by springs.

[0049] It should be noted that, since the cryogenic propellant is discharged in the direction of the discharge pipe 3 to prevent the generation of springs, it is preferred that the low-temperature storage tank 10 inside the equipment adapted for filling has redundant space;

[0050] It should be noted that in the existing pipeline, the discharge pipeline 8 has the function of reverse discharge of cryogenic propellant, but because its main function is to empty the filling pipeline 1 after the cryogenic storage tank 10 is filled and the filling and discharge valve on the equipment is closed, the discharge pipe diameter 8 needs to be compatible with the filling pipe diameter 1 to achieve rapid discharge; in the research process, if the discharge pipeline 8 of the DN150 pipeline is directly used to reversely discharge the cryogenic propellant, the excessively large pipe diameter will cause excessive discharge and tank decompression; therefore, it is necessary to improve the filling system of the cryogenic propellant.

[0051] The above is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A filling system for cryogenic propellant, characterized in that: include: A filling pipeline (1) is provided, the end of which is installed at the tank filling port; the filling pipeline (1) is connected to the low-temperature tank (10) through the tank filling port, and a first valve (2) is installed on the filling pipeline (1); A discharge assembly, the discharge assembly comprising a discharge pipe (3), the starting end of the discharge pipe (3) being installed between the first valve (2) of the filling pipeline (1) and the filling port of the tank, the end of the discharge pipe (3) being provided with a collecting pipe (6), and the discharge pipe (3) being provided with a second valve (4); The cryogenic tank (10) is provided with redundancy according to the volume of cryogenic propellant required for use, and the cryogenic tank (10) is filled up through the filling pipeline (1) and the redundant part is filled.

2. A cryogenic propellant filling system according to claim 1, characterized in that: The pipe of the drainage pipe (3) is DN40, and a temperature sensor and a pressure sensor are installed on the drainage pipe (3).

3. A cryogenic propellant filling system according to claim 1, characterized in that: The discharge pipe (3) is also provided with a third valve (5) which is a regulating valve, and the second valve (4) is a stop valve.

4. A cryogenic propellant filling system according to claim 1, characterized in that: The filling pipeline (1) is a DN150 pipeline, and the collecting pipe (6) is DN350.

5. A method for improving a cryogenic propellant filling system, characterized in that: It comprises a filling pipeline (1), the end of which is installed at the tank filling port, the filling pipeline (1) is connected to a low-temperature tank (10) through the tank filling port, and a first valve (2) is installed on the filling pipeline (1); The filling pipeline (1) is also provided with a fourth valve (7), the fourth valve (7) being located on a side of the first valve (2) away from the low-temperature storage tank (10), a discharge pipeline (8) being provided between the first valve (2) and the second valve (4), the discharge pipeline (8) being connected to a collecting pipe (6), and a fifth valve (9) being provided on the discharge pipeline (8); A discharge pipe (3) is installed and connected between the first valve (2) and the tank filling port, and a second valve (4) is provided on the discharge pipe (3).

6. The improved method for a cryogenic propellant filling system according to claim 5, characterized in that: The filling pipeline (1) and the discharge pipeline (8) are DN150 pipelines, the collecting pipe (6) is DN350, the pipeline of the discharge pipe (3) is DN40, and a temperature sensor and a pressure sensor are installed on the discharge pipe (3).

7. The improved method for a cryogenic propellant filling system according to claim 6, characterized in that: The discharge pipe (3) is also provided with a third valve (5) which is a regulating valve, and the second valve (4) is a stop valve.

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