A propellant depletion warning method for plate tanks

Abstract

The present application relates to a kind of propellant depletion early warning method for plate type tank, belong to spacecraft propulsion system technical field;Step one, aircraft is provided with plate type tank for storing propellant;First thermistor, second thermistor and heating band are pasted on the outer wall of the bottom of plate type tank;Step two, when aircraft enters in-orbit life end, whether it is judged to enter propellant depletion early warning according to propellant consumption;When judging to enter propellant depletion early warning, enter step three;Otherwise, continue to judge;Step three, carry out early warning measurement evaluation, give out the early warning information of propellant soon to be depleted or continue to carry out early warning measurement evaluation according to early warning measurement evaluation result;The present application is for spacecraft using plate type tank, can relatively accurately give the early warning information of spacecraft propellant soon to be depleted, so that spacecraft can be at ease deorbit while making full use of propellant.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft propulsion system technology and relates to a propellant depletion early warning method for plate-type tanks. Background Technology

[0002] In spacecraft propulsion systems, plate-type propellant tanks are a replacement for traditional mesh-type tanks. Compared to traditional mesh-type tanks, plate-type tanks have advantages such as simple structure, light weight, and good manufacturability. Therefore, in recent years, spacecraft, especially high-orbit communication satellites, have widely adopted plate-type tanks to replace traditional mesh-type tanks both domestically and internationally. However, while using plate-type tanks saves weight, it also sacrifices the ability to assess the propellant state inside the tank using the bubble bursting phenomenon of mesh-type tank screens.

[0003] Currently, spacecraft typically use methods such as the PVT method and the BK method to calculate the remaining propellant, determining whether the spacecraft's propellant is about to run out and requires immediate deorbiting. Calculation errors are generally on the order of tens of kilograms and have a certain degree of uncertainty. Large calculation errors could result in the waste of tens of kilograms of propellant, causing the satellite to deorbit prematurely. Furthermore, the uncertainty in the calculations could cause the spacecraft's propellant to run out earlier than expected, preventing deorbiting. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a propellant depletion early warning method for plate-type propellant tanks. For spacecraft using plate-type propellant tanks, this method can provide relatively accurate early warning information that the spacecraft's propellant is about to be depleted, so that the spacecraft can make full use of the propellant while being able to deorbit smoothly.

[0005] The solution of the present invention is: A method for early warning of propellant depletion in plate-type storage tanks includes: Step 1: The aircraft is equipped with a plate-type propellant storage tank; a first thermistor, a second thermistor, and a heating strip are attached to the outer wall of the bottom of the plate-type propellant storage tank; Step 2: When the spacecraft enters the end of its on-orbit lifespan, determine whether a propellant depletion warning has been triggered based on the propellant consumption. If a propellant depletion warning has been triggered, proceed to Step 3; otherwise, continue the assessment. Step 3: Conduct early warning measurement and assessment, and based on the results of the early warning measurement and assessment, determine whether to issue an early warning message that the propellant is about to run out or to continue conducting early warning measurement and assessment.

[0006] In the above-mentioned propellant depletion early warning method for plate-type tanks, in step one, vertical guide strips are uniformly arranged along the circumference of the outer wall of the plate-type tank; a first thermistor, a second thermistor, and a heating strip are pasted between any two adjacent guide strips; the first thermistor, the second thermistor, and the heating strip do not contact each other, and the first thermistor and the second thermistor are distributed vertically.

[0007] In the aforementioned propellant depletion early warning method for a plate-type storage tank, a tank accumulator is installed inside the plate-type storage tank, and the height of the tank accumulator is H; the height of the first thermistor or the second thermistor from the bottom of the plate-type storage tank is set to h; the value of h ranges from 1 / 3H. <h<1 / 2H。

[0008] In the above-mentioned propellant depletion early warning method for plate-type storage tanks, both the first thermistor and the second thermistor are located within the coverage area of ​​the heating zone; the distance between the first thermistor or the second thermistor and the heating zone is set as L1; the distance between the first thermistor and the second thermistor is set as L2; ​​the range of L1 is 10-20mm; and the range of L2 is 40-80mm.

[0009] In the above-mentioned propellant depletion early warning method for plate-type storage tanks, step two, the method for determining whether to enter the propellant depletion early warning state based on the propellant consumption, is as follows: Propellant consumption is measured in real time; when the propellant consumption of the plate tank exceeds 1 kg per measurement, or when the cumulative propellant consumption of the plate tank since the last measurement exceeds 1 kg, a propellant depletion warning is issued.

[0010] In the aforementioned propellant depletion early warning method for plate-type storage tanks, the specific method for early warning measurement and evaluation in step three is as follows: S1, duration t of waiting for the aircraft to be in a non-ignition state; S2. Turn on the heating belt and simultaneously collect the temperatures of the first and second thermistors; S3. Calculate the temperature rise rate a1' of the first thermistor and the temperature rise rate a2' of the second thermistor respectively. S4. Turn off the heating element; S5. Repeat S2-S3 to calculate the temperature rise rate a1 of the first thermistor and the temperature rise rate a2 of the second thermistor again. S6. Based on a1', a2', a1, and a2, establish an early warning judgment equation; S7. Based on the early warning judgment equation, provide early warning information that the propellant is about to be exhausted or continue to conduct early warning measurement and assessment.

[0011] In the above-mentioned propellant depletion early warning method for plate-type storage tanks, in S1, t is 1-1.5h.

[0012] In the above-mentioned propellant depletion early warning method for plate-type storage tanks, in step S2, the heating belt is turned on for 4-6 minutes, and the temperatures of the first thermistor and the second thermistor are collected for 5 minutes.

[0013] In the aforementioned propellant depletion early warning method for plate-type storage tanks, step S6 includes two equations in the early warning judgment equation: Equation 1: (a1'-a2') / (a1-a2)>1.5 Equation 2: a1' / a1>1.5, and a2' / a2>1.5.

[0014] In the above-mentioned propellant depletion early warning method for plate-type tanks, in step S7, when equation 1 or equation 2 is satisfied, an early warning message indicating that the propellant is about to be depleted is given; otherwise, the early warning measurement and evaluation continue.

[0015] The advantages of this invention compared to the prior art are: (1) This invention enables the issuance of early warning information when the remaining propellant in the spacecraft tank is less than 10kg, thereby maximizing the utilization of propellant; (2) The propellant depletion pre-tightening method of the present invention can reserve a small amount of propellant to ensure that the spacecraft has the ability to handle emergencies and deorbit; (3) This invention can increase the effective on-orbit usage time of a large number of spacecraft that use plate-type tanks by utilizing a small amount of resources, resulting in huge economic benefits. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the propellant depletion early warning process of the present invention. Figure 2 This is a schematic diagram showing the bonding of the first thermistor, the second thermistor, and the heating band in this invention; Figure 3 This is a schematic diagram showing the positional relationship between the first thermistor, the second thermistor, and the heating band of the present invention. Detailed Implementation

[0017] The present invention will be further described below with reference to the embodiments.

[0018] This invention provides a propellant depletion early warning method for plate-type propellant tanks. For spacecraft using plate-type propellant tanks, it can provide relatively accurate early warning information that the spacecraft's propellant is about to run out, enabling the spacecraft to make full use of the propellant while being able to deorbit smoothly.

[0019] Methods for early warning of propellant depletion in plate-type storage tanks, such as Figure 1As shown, the specific steps include the following: Step 1: The aircraft is equipped with a plate-type propellant storage tank; a first thermistor, a second thermistor, and a heating strip are attached to the outer wall at the bottom of the plate-type propellant storage tank.

[0020] like Figure 2 As shown, the outer wall of the plate-type storage tank is uniformly provided with vertical guide strips along the circumference; a first thermistor, a second thermistor, and a heating strip are attached between any two adjacent guide strips; the first thermistor, the second thermistor, and the heating strip do not contact each other, and the first and second thermistors are distributed vertically. A storage tank accumulator is installed inside the plate-type storage tank, with a height of H; the height of the first or second thermistor from the bottom of the plate-type storage tank is set to h; the value of h ranges from 1 / 3H. <h<1 / 2H。

[0021] Both the first and second thermistors are located within the coverage area of ​​the heating band; the distance between the first or second thermistor and the heating band is set as L1; the distance between the first and second thermistors is set as L2; ​​the range of L1 is 10-20mm; the range of L2 is 40-80mm. Figure 3 As shown.

[0022] Step 2: When the spacecraft enters the end of its on-orbit lifespan, determine whether to trigger a propellant depletion warning based on the propellant consumption. If a propellant depletion warning is triggered, proceed to Step 3; otherwise, continue the assessment.

[0023] The method for determining whether a propellant depletion warning has been triggered based on propellant consumption is as follows: Propellant consumption is measured in real time; when the propellant consumption of the plate tank exceeds 1 kg per measurement, or when the cumulative propellant consumption of the plate tank since the last measurement exceeds 1 kg, a propellant depletion warning is issued.

[0024] Step 3: Conduct early warning measurement and assessment, and based on the results of the early warning measurement and assessment, determine whether to issue an early warning message that the propellant is about to run out or to continue conducting early warning measurement and assessment.

[0025] The specific methods for early warning measurement and assessment are as follows: S1. Waiting time t for the aircraft to be in a non-ignition state; t is 1-1.5h.

[0026] S2. Turn on the heating element and simultaneously collect the temperatures of the first and second thermistors. Turn on the heating element for 4-6 minutes and simultaneously collect the temperatures of the first and second thermistors for 5 minutes.

[0027] S3. Calculate the temperature rise rate a1' of the first thermistor and the temperature rise rate a2' of the second thermistor respectively.

[0028] S4. Turn off the heating element; S5. Repeat S2-S3 to calculate the temperature rise rate a1 of the first thermistor and the temperature rise rate a2 of the second thermistor again.

[0029] S6. Based on a1', a2', a1, and a2, establish an early warning judgment equation.

[0030] The early warning judgment equation includes two equations: Equation 1: (a1'-a2') / (a1-a2)>1.5 Equation 2: a1' / a1>1.5, and a2' / a2>1.5.

[0031] S7. Based on the early warning judgment equation, provide early warning information that the propellant is about to be exhausted or continue to conduct early warning measurement and assessment.

[0032] If either Equation 1 or Equation 2 is satisfied, an early warning message indicating that the propellant is about to be exhausted is given; otherwise, the early warning measurement and assessment continue.

[0033] This invention presents a propellant depletion early warning method for plate-type tanks. This method utilizes the characteristic of plate-type tanks where, before propellant depletion, the remaining propellant is concentrated in the accumulator, and the tank walls are essentially uncovered. Through a thermal response method, it senses whether the bottom wall of the tank is covered with propellant, thereby assessing whether the propellant in the tank is about to be depleted, with only a small amount (approximately 3L) of propellant remaining in the accumulator. Based on this, an early warning message indicating that the tank's propellant is about to run out is issued.

[0034] Example The positions for attaching the two heaters and heating strips are shown in the attached diagram. Figure 2 As shown, the thermistors are located between two adjacent flow guides in the plate-type storage tank, near the outer wall surface of the tank bottom. The height h of the center positions of thermistors 1 and 2 from the bottom of the tank is related to the height H of the tank's accumulator. H is taken as 5 / 12H. The relative positions of the thermistors and heating belts are shown in the attached figure. Figure 3 As shown. Thermistors 1 and 2 are both located within the heating band's coverage area. The distance L1 between each thermistor and the heating band is 15mm. The distance L2 between thermistors 1 and 2 is 60mm.

[0035] On-orbit measurement and evaluation steps: Stabilize for 1 hour — Turn on the heating belt for 5 minutes and simultaneously collect the temperature value of the thermistor for 5 minutes — Calculate the temperature rise slope of the thermistor and compare it with the previous measurement for evaluation.

[0036] Early warning criteria for when propellant in the tank is about to run out: S1: (a1'- a2') / (a1- a2)>1.5, Or S2: a1' / a1>1.5 and a2' / a2>1.5.

[0037] If either S1 or S2 is met, a warning message indicating that the propellant is about to be exhausted is given; otherwise, the warning measurement and assessment continue.

[0038] Currently, spacecraft both domestically and internationally generally employ methods such as the PVT and BK methods to calculate remaining propellant levels, determining whether the spacecraft's propellant is about to run out and necessitating immediate deorbiting. The PVT and BK methods typically have a calculation error of around 50 kg and exhibit a degree of uncertainty. To ensure safe deorbiting, spacecraft generally determine the deorbiting timing while considering the upper limit of the calculation error, which likely results in the waste of approximately 50 kg of remaining propellant, equivalent to a one-year loss of the spacecraft's lifespan. This invention proposes a propellant depletion early warning method for plate-type propellant tanks. This method can provide an early warning when the remaining propellant in the spacecraft's tank is less than 10 kg. This maximizes propellant utilization while reserving a small amount of propellant to ensure the spacecraft has emergency response and deorbiting capabilities. Therefore, this invention can increase the effective on-orbit operating time of spacecraft using a large number of plate-type propellant tanks with limited resources, generating significant economic benefits.

[0039] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A propellant depletion early warning method for plate-type storage tanks, characterized in that: include: Step 1: The aircraft is equipped with a plate-type propellant storage tank; a first thermistor, a second thermistor, and a heating strip are attached to the outer wall of the bottom of the plate-type propellant storage tank; Step 2: When the spacecraft enters the end of its on-orbit lifespan, determine whether to enter the propellant depletion warning stage based on the propellant consumption. If the propellant depletion warning is triggered, proceed to step three; otherwise, continue with the assessment. Step 3: Conduct early warning measurement and assessment, and based on the results of the early warning measurement and assessment, determine whether to issue an early warning message that the propellant is about to run out or to continue conducting early warning measurement and assessment.

2. The propellant depletion early warning method for plate-type storage tanks according to claim 1, characterized in that: In step one, vertical guide strips are uniformly arranged along the circumference of the outer wall of the plate tank; a first thermistor, a second thermistor, and a heating strip are pasted between any two adjacent guide strips; the first thermistor, the second thermistor, and the heating strip do not contact each other, and the first thermistor and the second thermistor are distributed vertically.

3. The propellant depletion early warning method for plate-type storage tanks according to claim 2, characterized in that: The plate-type storage tank is equipped with a liquid accumulator inside, and the height of the liquid accumulator is H; the height of the first or second thermistor from the bottom of the plate-type storage tank is set to h; the value of h is 1 / 3H. <h<1 / 2H。 4. The propellant depletion early warning method for plate-type storage tanks according to claim 2, characterized in that: Both the first and second thermistors are located within the coverage area of ​​the heating band; the distance between the first or second thermistor and the heating band is set as L1; the distance between the first and second thermistors is set as L2; ​​the range of L1 is 10-20mm; the range of L2 is 40-80mm.

5. A propellant depletion early warning method for plate-type storage tanks according to claim 1, characterized in that: In step two, the method for determining whether to enter the propellant depletion warning state based on the propellant consumption is as follows: Propellant consumption is measured in real time; when the propellant consumption of the plate tank exceeds 1 kg per measurement, or when the cumulative propellant consumption of the plate tank since the last measurement exceeds 1 kg, a propellant depletion warning is issued.

6. The propellant depletion early warning method for plate-type storage tanks according to claim 1, characterized in that: In step three, the specific method for early warning measurement and assessment is as follows: S1, duration t of waiting for the aircraft to be in a non-ignition state; S2. Turn on the heating belt and simultaneously collect the temperatures of the first and second thermistors; S3. Calculate the temperature rise rate a1' of the first thermistor and the temperature rise rate a2' of the second thermistor respectively. S4. Turn off the heating element; S5. Repeat S2-S3 to calculate the temperature rise rate a1 of the first thermistor and the temperature rise rate a2 of the second thermistor again. S6. Based on a1', a2', a1, and a2, establish an early warning judgment equation; S7. Based on the early warning judgment equation, provide early warning information that the propellant is about to be exhausted or continue to conduct early warning measurement and assessment.

7. A propellant depletion early warning method for plate-type storage tanks according to claim 6, characterized in that: In S1, t is 1-1.5h.

8. A propellant depletion early warning method for plate-type storage tanks according to claim 6, characterized in that: In step S2, the heating band is turned on for 4-6 minutes, and the temperatures of the first and second thermistors are collected for 5 minutes simultaneously.

9. A propellant depletion early warning method for plate-type storage tanks according to claim 6, characterized in that: In S6, the early warning judgment equation includes two equations: Equation 1: (a1'-a2') / (a1-a2)>1.5 Equation 2: a1' / a1>1.5, and a2' / a2>1.

5.

10. A propellant depletion early warning method for plate-type storage tanks according to claim 9, characterized in that: In S7, when Equation 1 or Equation 2 is satisfied, a warning message indicating that the propellant is about to be exhausted is given. Otherwise, continue with the early warning measurement and assessment.

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