Drainage method of airplane water system

Abstract

The invention relates to the technical field of civil aviation aircrafts, and discloses a drainage method of an airplane water system, which comprises the following steps: S1, opening all drainage ports until no water is discharged from the airplane water system under the action of gravity; s2, any water outlet below the machine body is connected with negative pressure water drainage equipment, and all water inlets and other water outlets below the machine body are closed; s3, setting the negative-pressure drainage pressure of the negative-pressure drainage equipment at the drainage port; s4, opening water utilization equipment at each position in the aircraft, so that each position of the aircraft water system and the negative pressure drainage equipment form a passage through the drainage port; and S5, the steps S2-S4 are repeated, and the negative-pressure drainage equipment is sequentially connected with other drainage ports below the aircraft body till residual water in the aircraft water system is completely drained. The method has the beneficial effects that the drainage efficiency is improved, the workload of an airline department is reduced, no residual water in a water system is ensured, the drainage cost is reduced, and the carbon emission is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of civil aircraft, and in particular to a drainage method for an aircraft water system. Background Art

[0002] In northern my country, the temperature is low in winter. After a day's operation, if the water in the water system is not completely drained during the post-flight work, the water in the water system will freeze due to the low temperature. After the water system freezes, the aircraft will not be able to add water before the next day's flight, affecting the normality of the flight. In serious cases, it may even cause damage to the water system components. Therefore, civil aircraft operating in the north need to completely drain the water in the water system after each flight in winter to prevent freezing.

[0003] The main process of draining water from the existing aircraft water system is: using gravity to drain the water in the water system from the drain port at the bottom of the aircraft, and the residual water in the water system is generally drained by APU pressurization. In this drainage process, gravity drainage takes no more than 20 minutes, and most of the time is used to discharge the residual water. It is necessary to perform the water system pressurization and drainage steps many times, which takes about 1.5 hours, and the drainage efficiency is low. At the same time, in the APU pressurization and drainage stage, most of the time is consumed waiting for the water system to be pressurized to build pressure. There is very little effective drainage time, which increases the workload of the route department. In addition, this drainage method cannot guarantee that the water in the water system is drained cleanly every time. It is still possible that the water system pipeline will freeze due to incomplete drainage, affecting the normality of the flight and even damaging the water system components. In addition, the APU needs to operate continuously when performing the drainage work. Due to the large number of aircraft and the high frequency of drainage, huge fuel costs, labor costs, APU loss costs, high drainage costs, and a large amount of carbon emissions are generated. Summary of the invention

[0004] The purpose of the present invention is to provide a drainage method for an aircraft water system, improve drainage efficiency, reduce the workload of the airline department, ensure that there is no residual water in the water system, and at the same time, reduce drainage costs and carbon emissions.

[0005] In order to achieve the above object, the present invention provides a drainage method for an aircraft water system, wherein the aircraft water system is provided with a plurality of drainage ports under the fuselage, comprising the following steps:

[0006] S1. Open all the drain ports until no water is discharged from the aircraft water system under the action of gravity;

[0007] S2. Connect any drainage outlet under the fuselage to negative pressure drainage equipment, and close all water inlets and other drainage outlets under the fuselage;

[0008] S3, setting the negative pressure drainage pressure of the negative pressure drainage device at the drainage outlet;

[0009] S4, opening various water-using devices inside the aircraft, so that various locations of the aircraft water system form a passage with the negative pressure drainage device through the drainage port, and under the action of the negative pressure drainage pressure of the negative pressure drainage device, the residual water in the aircraft water system is sucked out through the negative pressure drainage device;

[0010] S5. Repeat steps S2-S4 to connect the negative pressure drainage equipment to other drainage ports under the fuselage in sequence until all the remaining water in the aircraft water system is drained.

[0011] Furthermore, the negative pressure drainage equipment includes an air pump, a power supply and an ejector, and the ejector is used to connect with the drainage port to form negative pressure suction drainage.

[0012] Furthermore, step S3 includes

[0013] S31, establish a flow field simulation model of the ejector, and determine the negative pressure drainage pressure: the ejector includes a pressure inlet, a velocity inlet, a pressure outlet and a throat, the velocity inlet is connected to the air pump to introduce a high-speed airflow, the negative pressure drainage pressure of the velocity inlet is adjusted, and the pressure inlet is connected to a drain port; record the simulated negative pressure value formed when the high-speed airflow enters the throat through the velocity inlet under the action of different negative pressure drainage pressures; the residual water in the aircraft water system is discharged from the pressure outlet through the drain port from the pressure inlet under the negative pressure at the throat;

[0014] S32. Using the AI ​​MSIM software, a negative pressure drainage model of the aircraft water system is established. A humidity sensor is set in each pipeline of the negative pressure drainage model, and a preset humidity threshold is set. The drainage flow rate of the drain port is adjusted according to the simulated negative pressure value. Within the preset drainage time, the actual humidity value of the humidity sensor in each pipeline is recorded. If all of the actual humidity values ​​are within the preset humidity threshold range, the negative pressure drainage pressure meets the drainage demand. Otherwise, the drainage demand is not met.

[0015] Furthermore, the negative pressure drainage pressure ranges from 2 bar to 6 bar.

[0016] Furthermore, the simulated negative pressure value ranges from (-14281Pa) to (-42480Pa).

[0017] Furthermore, the diameter of the velocity inlet is d1, the diameter of the pressure inlet is d2, the diameter of the pressure outlet is d3, and the diameter of the throat is d4, satisfying d1:d2:d3:d4=5:2.5:5:1.

[0018] Furthermore, the velocity of the high-speed airflow at the velocity inlet is between 50m / s and 70m / s.

[0019] Furthermore, a gas-liquid separator is provided at the water outlet of the negative pressure drainage equipment.

[0020] Compared with the prior art, the drainage method of an aircraft water system in an embodiment of the present invention has the following beneficial effects: water in the aircraft water system is initially drained by using gravity, and then the negative pressure water discharge device is sequentially connected with the drainage ports under the fuselage, and the residual water in the water system is drained by using negative pressure suction, thereby avoiding residual water in the water system, eliminating the need to use APU for pressurized drainage, shortening drainage time, improving drainage efficiency, reducing the workload of the airline department, reducing drainage costs, and reducing carbon emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flow chart of a drainage method for an aircraft water system according to an embodiment of the present invention;

[0022] Figure 2 is a structural principle diagram of an ejector in a drainage method for an aircraft water system according to an embodiment of the present invention;

[0023] Figure 3 is a pressure cloud diagram of an ejector in a drainage method for an aircraft water system according to an embodiment of the present invention;

[0024] Figure 4 1 is a diagram of a negative pressure drainage model of an aircraft water system according to an embodiment of the present invention.

[0025] In the figure, 1, ejector; 11, velocity inlet; 12, pressure inlet; 13, pressure outlet; 14, throat. DETAILED DESCRIPTION

[0026] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0027] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "inside", "outside", etc. used in the present invention to indicate the orientation or positional relationship are based on the 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 referred devices and elements must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] In the description of the present invention, it should be understood that the present invention uses the terms "first", "second", etc. to describe various information, but these information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0029] like Figure 1 As shown, a preferred embodiment of the present invention is a drainage method for an aircraft water system, wherein the aircraft water system is provided with a plurality of drainage ports under the fuselage, comprising the following steps:

[0030] S1. Open all the drain ports until no water is discharged from the aircraft water system under the action of gravity;

[0031] S2. Connect any drainage outlet under the fuselage to negative pressure drainage equipment, and close all water inlets and other drainage outlets under the fuselage;

[0032] S3, setting the negative pressure drainage pressure of the negative pressure drainage device at the drainage outlet;

[0033] S4, opening various water-using devices inside the aircraft, so that various locations of the aircraft water system form a passage with the negative pressure drainage device through the drainage port, and under the action of the negative pressure drainage pressure of the negative pressure drainage device, the residual water in the aircraft water system is sucked out through the negative pressure drainage device;

[0034] S5. Repeat steps S2-S4 to connect the negative pressure drainage equipment to other drainage ports under the fuselage in sequence until all the remaining water in the aircraft water system is drained.

[0035] Among them, in step S1, the water in the aircraft water system is initially drained by gravity. In steps S2, S3, and S4, since negative pressure is always formed at the drain outlet by the negative pressure drainage equipment during the drainage process, it is ensured that there is no residual water in the aircraft water system, thereby avoiding ice formation in the water system pipes due to incomplete drainage, affecting the normal operation of the flight, and even damaging the water system components.

[0036] Specifically, since the conventional vacuum pump and centrifugal pump are only applicable to a single medium when forming negative pressure, which can only be one of gas or liquid, the applicability to the working condition of gas-liquid mixture is poor. Therefore, in this embodiment, the negative pressure drainage equipment includes an air pump, a power supply and an ejector 1, wherein the ejector 1 is used to communicate with the drainage port to form negative pressure suction drainage.

[0037] Furthermore, in order to ensure that the negative pressure provided by the negative pressure drainage device can satisfy the requirement of draining the residual water in the water system, that is, to set a reasonable negative pressure drainage pressure to ensure that the residual water in the water system is drained, it is necessary to simulate the process of draining water through the ejector. In this embodiment, step S3 includes:

[0038] S31. Establish the flow field simulation model of the ejector and determine the negative pressure drainage pressure: refer to Figure 2 The ejector 1 includes a velocity inlet 11, a pressure inlet 12, a pressure outlet 13 and a throat 14. The velocity inlet 11 is connected to an air pump to introduce a high-speed airflow. The negative pressure drainage pressure of the velocity inlet 11 is adjusted. The pressure inlet 12 is connected to a drain port. The simulated negative pressure value formed when the high-speed airflow passes through the velocity inlet 11 into the throat 14 under the action of different negative pressure drainage pressures is recorded. The residual water in the aircraft water system is discharged from the pressure inlet 12 through the drain port and the negative pressure at the throat 14 from the pressure outlet 13.

[0039] S32, see Figure 4 , using AI MSIM software, a negative pressure drainage model of the aircraft water system is established, humidity sensors are set in each pipeline of the negative pressure drainage model, and a preset humidity threshold is set. The drainage flow of the drain port is adjusted according to the simulated negative pressure value. Within the preset drainage time, the actual humidity value of the humidity sensor in each pipeline is recorded. If they are all within the preset humidity threshold range, the negative pressure drainage pressure meets the drainage demand, otherwise, it does not meet the drainage demand.

[0040] The negative pressure drainage model of the ejector and the water system is simulated to determine the pressure range of the negative pressure drainage. Specifically, in this embodiment, refer to Figure 3 The negative pressure drainage pressure ranges from 2bar to 6bar. If the negative pressure drainage pressure is less than 2bar, water will remain in the water system. If the negative pressure drainage pressure is greater than 6bar, the negative pressure inside the pipeline in the water system is too large, which may easily lead to the rupture of the pipeline in the pipeline or damage to some water-using equipment. As the value of the negative pressure drainage pressure changes, the simulated negative pressure value of the throat 14 changes synchronously. When the negative pressure drainage pressure is 2bar, 3bar, 4bar, 5bar, and 6bar, the change of the simulated negative pressure value is as shown in the following table. It can be seen that in this embodiment, the simulated negative pressure value ranges from (-14281Pa) to (-42480Pa), where the units bar and Pa can be converted, 1bar = 100000Pa.

[0041] Serial number Negative drainage pressure (unit bar) Simulated negative pressure value (unit: Pa) 1 2bar -14281 2 3bar -21346 3 4bar -28400 4 5bar -35445 5 6bar -42480

[0042] Furthermore, in order to facilitate the design of the structure of the ejector to meet the drainage requirements of the present invention, refer to Figure 2, the diameter of the velocity inlet 11 is d1, the diameter of the pressure inlet 12 is d2, the diameter of the pressure outlet 13 is d3, and the diameter of the throat 14 is d4, satisfying d1: d2: d3: d4 = 5: 2.5: 5: 1. Furthermore, in order to ensure that the high-speed airflow drives the water in the ejector to be quickly discharged, the flow rate of the high-speed airflow at the velocity inlet 11 is between 50m / s and 70m / s. Preferably, in step S31, the flow rate of the high-speed airflow is 60m / s.

[0043] Furthermore, in order to confirm that the residual water in the aircraft water system is completely drained, a gas-liquid separator is provided at the water outlet of the negative pressure drainage equipment. Before drainage begins, the mass M of the water in the water system is recorded, and then gravity drainage is started, and the drainage mass m1 during gravity drainage is recorded. The drainage mass m2 of the gas-liquid separator during the negative pressure drainage equipment is also recorded until the drainage mass of the gas-liquid separator no longer increases within a certain period of time. If M=m1+m2 is satisfied, it means that the residual water in the water system is completely drained.

[0044] In summary, the embodiments of the present invention provide a method for draining an aircraft water system, which utilizes gravity to initially drain the water in the aircraft water system, and then connects with the drainage ports under the fuselage in sequence through a negative pressure water discharge device, and drains the residual water in the water system by negative pressure suction, thereby avoiding residual water in the water system. There is no need to use an APU for pressurized drainage, thus shortening the drainage time, improving the drainage efficiency, reducing the workload of the airline department, reducing the drainage cost, and reducing carbon emissions.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for draining water from an aircraft water system, wherein the aircraft water system is provided with a plurality of drain ports under the fuselage, wherein: The following steps are involved: S1. Open all the drain ports until no water is discharged from the aircraft water system under the action of gravity; S2. Connect any drainage outlet under the fuselage to negative pressure drainage equipment, and close all water inlets and other drainage outlets under the fuselage; S3, setting the negative pressure drainage pressure of the negative pressure drainage device at the drainage outlet; S4, opening various water-using devices inside the aircraft, so that various locations of the aircraft water system form a passage with the negative pressure drainage device through the drainage port, and under the action of the negative pressure drainage pressure of the negative pressure drainage device, the residual water in the aircraft water system is sucked out through the negative pressure drainage device; S5. Repeat steps S2-S4 to connect the negative pressure drainage equipment to other drainage ports under the fuselage in sequence until all the remaining water in the aircraft water system is drained.

2. The method for draining water from an aircraft water system according to claim 1, characterized in that: The negative pressure drainage equipment comprises an air pump, a power supply and an ejector, and the ejector is used to be connected with the drainage port to form negative pressure suction drainage.

3. The method for draining water from an aircraft water system according to claim 2, wherein: Step S3 includes S31, establish a flow field simulation model of the ejector, and determine the negative pressure drainage pressure: the ejector includes a velocity inlet, a pressure inlet, a pressure outlet and a throat, the velocity inlet is connected to the air pump to introduce a high-speed airflow, the negative pressure drainage pressure of the velocity inlet is adjusted, and the pressure inlet is connected to a drain outlet; record the simulated negative pressure value formed when the high-speed airflow passes through the velocity inlet into the throat under the action of different negative pressure drainage pressures; the residual water in the aircraft water system is discharged from the pressure outlet through the drain outlet from the pressure inlet under the negative pressure at the throat; S32. Use AIMSIM software to establish a negative pressure drainage model of the aircraft water system, set a humidity sensor in each pipeline of the negative pressure drainage model, and set a preset humidity threshold value, adjust the drainage flow of the drain port according to the simulated negative pressure value, and record the actual humidity value of the humidity sensor in each pipeline within a preset drainage time. If all of the humidity values ​​are within the preset humidity threshold range, the negative pressure drainage pressure meets the drainage demand, otherwise, the drainage demand is not met.

4. The method for draining water from an aircraft water system according to claim 3, wherein: The negative pressure drainage pressure ranges from 2 bar to 6 bar.

5. The method for draining water from an aircraft water system according to claim 4, wherein: The simulated negative pressure value ranges from (-14281Pa) to (-42480Pa).

6. The method for draining water from an aircraft water system according to claim 3, wherein: The diameter of the velocity inlet is d1, the diameter of the pressure inlet is d2, the diameter of the pressure outlet is d3, and the diameter of the throat is d4, satisfying d1:d2:d3:d4=5:2.5:5:

1.

7. The method for draining water from an aircraft water system according to claim 3, wherein: The velocity of the high-speed airflow at the velocity inlet is between 50m / s and 70m / s.

8. The method for draining water from an aircraft water system according to claim 1, wherein: The water outlet of the negative pressure drainage equipment is provided with a gas-liquid separator.

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