Micro-electro-mechanical system phase change material driving gas micro-flow regulating valve for satellite electric propulsion

Abstract

The utility model provides a gas flow regulating valve driven by a phase-change material based on a micro electro mechanical system for satellite electric propulsion, which comprises a base, a heating sheet, a heater, the phase-change material, a deformation sheet, an outlet sheet and an electrode, and the outlet sheet, the deformation sheet, the phase-change material, the heater, the heating sheet and the base are connected in sequence; a base through hole is formed in the base, a heating piece through hole is formed in the heating piece, a deformation piece groove and a deformation piece through hole are formed in the deformation piece, a control space and a flow hole communicated with the control space are formed in the outlet piece, and the base through hole, the heating piece through hole, the deformation piece through hole, the control space and the flow hole are sequentially communicated. The heater is electrified and heated to enable the phase change material to expand so as to drive the deformation piece to elastically deform in the direction close to the flow hole, and therefore gas flow control is achieved. The flow control device is simple in process, small in size, short in response time and small in control voltage, and automatic flow control is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas flow regulating valve, in particular to a gas flow regulating valve based on micro-electro-mechanical system phase change material driving for satellite electric propulsion. BACKGROUND

[0002] The electric propulsion system has the advantages of high specific impulse, light weight, and low consumption of working medium, and has been widely used on satellite platforms in various countries. The application of space electric propulsion technology has gradually changed from controlling the stationary orbit position to maintaining the satellite transfer orbit after the satellite separates from the rocket, orbit position maintenance after the satellite enters the orbit, momentum wheel unloading, and orbit departure during the shaping life period. The change of space tasks requires the electric propulsion system to have the ability of multi-mode and variable thrust. With the help of a flow regulating module, the electric propulsion system can realize multi-mode regulation of xenon working medium flow to meet the task requirements of multi-mode and variable thrust.

[0003] Micro and nano satellites can perform tasks such as technology demonstration, earth observation, and communication, and have the advantages of short development cycle, low cost, flexible launch, and low carrying requirement, which have obvious military and scientific values. The propulsion system of micro and nano satellites is mainly used for tasks such as orbit position maintenance, orbit transfer, and formation flight, and different tasks require the propulsion system to provide thrust in different ranges. The propulsion system that is more suitable for such tasks is a micro cold gas propulsion system, which has a thrust in the order of millinewton to newton. With the help of a flow regulating module, the micro cold gas propulsion system can realize a large range of thrust regulation.

[0004] Traditional flow regulating modules mainly realize flow regulation through proportional valves, such as electromagnetic proportional valves, magnetic hysteresis proportional valves, and piezoelectric proportional valves. However, the weight and volume limitations make it impossible for traditional proportional valves to meet the requirements of large-scale accurate regulation of gas flow under small-size conditions. For micro fluid systems, micro valves based on micro-electro-mechanical systems are designed, such as micro electromagnetic valves, micro piezoelectric ceramic valves, and micro shape memory alloy valves. Although the above micro valves meet the small-size use scenarios, they still have problems such as complex process, excessively high driving voltage, and excessively long response time.

[0005] In summary, the existing gas flow regulating modules still have the following problems to be improved:

[0006] 1. The flow regulating modules of conventional size have limitations in weight and volume, and cannot meet the small-size use scenarios;

[0007] 2. The micro electromagnetic valves based on micro-electro-mechanical systems have a complex process;

[0008] 3. The micro piezoelectric ceramic valves based on micro-electro-mechanical systems have excessively high driving voltage;

[0009] 4. Micro shape memory alloy valve based on micro electro mechanical system has long response time. SUMMARY

[0010] In view of the defects in the prior art, the purpose of the present application is to provide a micro electro mechanical system based phase change material driven gas flow regulating valve for satellite electric propulsion.

[0011] According to the micro electro mechanical system based phase change material driven gas flow regulating valve for satellite electric propulsion provided by the present application, the base 1, the heating sheet 2, the heater 3, the phase change material 4, the deformation sheet 5, the outlet sheet 6 and the electrode 8 are sequentially connected.

[0012] The outlet sheet 6, the deformation sheet 5, the phase change material 4, the heater 3, the heating sheet 2 and the base 1 are sequentially connected.

[0013] The base 1 is provided with a base through hole 11, the heating sheet 2 is provided with a heating sheet through hole 21, the deformation sheet 5 is provided with a deformation sheet groove 51, a deformation sheet through hole 52 and a corrugated adjusting diaphragm 53, and the outlet sheet 6 is provided with a control space 61 and a flow hole 62 in communication with the control space 61.

[0014] The base through hole 11, the heating sheet through hole 21, the deformation sheet through hole 52, the control space 61 and the flow hole 62 are sequentially connected in communication.

[0015] The deformation sheet 5 and the heating sheet 2 enclose the deformation sheet groove 51 into a sealed space, and the phase change material 4 is filled in the deformation sheet groove 51.

[0016] The phase change material 4 and the heating sheet 2 are provided with the heater 3.

[0017] The two ends of the heater 3 are respectively connected with the electrode 8.

[0018] When the heater 3 is powered and heated, the phase change material 4 expands to drive the deformation sheet 5 to elastically deform in the direction close to the flow hole 62.

[0019] The heating sheet 2 adopts borosilicate glass material, and the heating sheet through hole 21 is two arc-shaped through holes which are axisymmetric to each other.

[0020] The heater 3 adopts platinum material, and the heater 3 is a serpentine structure formed by a plurality of parallel equidistant resistance wires connected in series.

[0021] The heating sheet 2 and the heater 3 are connected by metal deposition.

[0022] The deformation sheet 5 is made of silicon wafer, and the deformation sheet groove 51 is a cylindrical space.

[0023] The deformation sheet through hole 52 is an arc-shaped through hole and the number is two.

[0024] Two deformation sheet through holes 52 are symmetrically arranged on both sides of the deformation sheet groove 51.

[0025] The deformation part of the deformation sheet is a corrugated adjusting diaphragm (53).

[0026] Preferably, the base 1 is made of stainless steel material, and the base through hole 11 is a stepped through hole.

[0027] The base 1 is glued with the heating sheet 2.

[0028] Preferably, the phase change material 4 is paraffin.

[0029] Preferably, the gas flow through the flow hole 62 is controlled at 0-2g / s.

[0030] Preferably, the outlet sheet 6 is made of silicon wafer, and the control space 61 and the flow hole 62 are both cylindrical spaces.

[0031] Preferably, a valve cover 7 is further included, and the valve cover 7 is installed on the outlet sheet 6.

[0032] The valve cover 7 is provided with a valve cover through hole 71, which is in communication with the flow hole 62.

[0033] Preferably, the valve cover 7 is glued with the outlet sheet 6.

[0034] The valve cover 7 is made of stainless steel material.

[0035] Compared with the prior art, the present application has the following beneficial effects:

[0036] 1. The present application realizes the control of gas flow by using phase change material, and has simple process control, small volume, fast response time, small control voltage, realizes automatic precise control, and has strong practicability.

[0037] 2. The present application can select multiple structure forms according to actual needs, and has simple structure, flexibility and practicability.

[0038] 3. The structure is compact, multiple connection and sealing modes are adopted, and the miniaturization of the flowmeter can be realized.

[0039] 4. The present application can realize the control range of gas flow at 0-2g / s, and realizes the micro-flow control of the gas regulating valve. BRIEF DESCRIPTION OF DRAWINGS

[0040] Other features, objects and advantages of the present application will become more apparent through reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0041] Figure 1 is a structural schematic view of the present application;

[0042] Figure 2Figure 1 is a schematic diagram of an explosion of the present application;

[0043] Figure 3 Figure 2 is a schematic diagram of a structure of the present application;

[0044] Figure 4 Figure 3 is a schematic diagram of a structure of a deformation sheet 5 of the present application;

[0045] Figure 5 Figure 4 is a schematic diagram of a structure of a heater 3 of the present application;

[0046] Figure 6 Figure 5 is a schematic diagram of a structure of a heating sheet 2 of the present application.

[0047] The figures show:

[0048]

[0049] DETAILED DESCRIPTION

[0050] The present application will be described in detail below with specific embodiments. The following examples will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present application. These are all within the scope of protection of the present application.

[0051] According to the micro-electro-mechanical system-based phase change material driven gas flow regulating valve for satellite electric propulsion provided by the present application, as shown in Figure 1As shown, it comprises a base 1, a heating sheet 2, a heater 3, a phase change material 4, a deformation sheet 5, an outlet sheet 6, a valve cover 7 and an electrode 8, the valve cover 7, the outlet sheet 6, the deformation sheet 5, the phase change material 4, the heater 3, the heating sheet 2 and the base 1 are sequentially connected; the base 1 is provided with a base through hole 11, the heating sheet 2 is provided with a heating sheet through hole 21, the deformation sheet 5 is provided with a deformation sheet recess 51, a deformation sheet through hole 52 and a corrugated adjusting diaphragm 53, the outlet sheet 6 is provided with a control space 61 and a flow hole 62 in communication with the control space 61, and the valve cover 7 is provided with a valve cover through hole 71, wherein the base through hole 11, the heating sheet through hole 21, the deformation sheet through hole 52, the control space 61, the flow hole 62 and the valve cover through hole 71 are sequentially communicated, the deformation sheet 5 and the heating sheet 2 enclose the deformation sheet recess 51 into a sealed space, the phase change material 4 is filled in the deformation sheet recess 51, the heater 3 is arranged between the phase change material 4 and the heating sheet 2, the two ends of the heater 3 are respectively connected with the electrode 8, when the heater 3 is powered and heated, the phase change material 4 expands to drive the deformation sheet 5 to elastically deform in the direction close to the flow hole 62. The application realizes the control of the gas flow by using the phase change material, has simple process control, small volume, fast response time, small control voltage, realizes the automatic precise control and has strong practicability.

[0052] Further, the deformation sheet 5 is deformed by the expansion of the phase change material 4 to realize the control of the flow of the gas through the flow hole 62, the application can realize the control range of the gas flow of 0-2g / s, and realizes the micro-flow control of the gas regulating valve.

[0053] Specifically, as Figure 4As shown, the deformation sheet 5 is made of a silicon wafer, the deformation sheet groove 51 is a cylindrical space, and the deformation sheet through hole 52 is an arc-shaped through hole. The deformation sheet 5 is made of a conventional silicon wafer. As a key component for adjusting the gas passage, the silicon wafer material has a mature micro-processing technology and high processing precision. The thickness of the corrugated adjusting diaphragm 53 in the deformation sheet can be controlled to the micron level. In a preferred example, the deformation sheet groove 51 is arranged at the center of the deformation sheet 5. The depth of the deformation sheet groove 51 needs to ensure that the thickness of the adjusting diaphragm 53 meets the deformation requirement. The deformation sheet groove 51 is used to fill the phase change material 4. Two arc-shaped through holes, i.e., the deformation sheet through hole 52, are symmetrically arranged on both sides of the deformation sheet groove 51. The deformation sheet through hole 52 is used to connect the heating sheet through hole 21, the control space 61, and the gas passage of the flow hole 62. The deformation sheet through hole 52 is arranged opposite to the arc-shaped through hole of the heating sheet through hole 21. In a variant, the deformation sheet through hole 52 and the heating sheet through hole 21 are respectively circular through holes. The deformation sheet through hole 52 and the heating sheet through hole 21 can be arranged in various forms, such as triangular through holes, quadrilateral through holes, etc. However, in order to make the entire gas flow regulating valve smaller, the arc-shaped through hole is selected, which is simple in structure and flexible and practical in use. The adjusting diaphragm 53 adopts a corrugated structure. Under the condition of the same diameter and thickness, the corrugated diaphragm is more rigid and has a longer stroke displacement than the flat diaphragm, and has a wider range of use.

[0054] Specifically, as shown in Figure 1 , the base 1 is made of stainless steel material, the base through hole 11 is a stepped through hole, which is used as a support body of the regulating valve for placing other components. The heating sheet 2 is arranged on the base 1, and the heating sheet 2 is used to fix the heater 3. In a preferred example, the base through hole 11 is a circular through hole arranged in two stepped forms along the axis direction of the base 1. The base 1 is glued to the heating sheet 2. The smaller diameter part of the base through hole 11 is used as an upstream passage of the gas. The gas enters the gas flow regulating valve from the upstream passage. The larger diameter part of the base through hole 11 cooperates with the heating sheet through hole 21 of the heating sheet 2. The gas enters the heating sheet through hole 21 through the base 1.

[0055] Further, as shown in Figure 1 , Figure 6 , the heating sheet 2 is used as a substrate of the deposited heater 3, and the material is borosilicate glass. On one hand, this material is convenient for the deposition process of the heater 3. On the other hand, it is also convenient for the subsequent wafer bonding process. In a preferred example, the heating sheet 2 is provided with the heating sheet through hole 21. The heating sheet through hole 21 is two arc-shaped through holes that are axially symmetrical to each other. The heating sheet through hole 21 is an arc-shaped structure. The heating sheet through hole 21 is used to connect the base through hole 11 and the deformation sheet through hole 52.

[0056] Specifically, as shown in Figure 1As shown in the figure, the heater 3 is used to heat the phase change material 4, and the heater 3 is made of metal platinum, which has high resistivity and is resistant to oxidation, and the processing technology is mature. In a preferred example, the heater 3 is a serpentine structure formed by a plurality of parallel equidistant resistance wires connected in series, as shown in the figure Figure 5 As shown in the figure, the heater 3 is designed in a serpentine reciprocating resistance wire structure, which makes the temperature distribution radially distributed along the center, and the processing technology has high reliability. The heater 3 is placed on the heating sheet 2 and used to heat the phase change material 4, the phase change material 4 is placed in the deformation sheet groove 51, and the other side is in contact with the heater 3. The deformation sheet 5 is placed on the heating sheet 2, and the heater 3 and the deformation sheet 5 are concentrically matched. The outlet sheet 6 is placed on the deformation sheet 5, and the outlet sheet 6 and the deformation sheet 5 are concentrically matched. The valve cover 7 is placed on the outlet sheet 6, and the valve cover 7 and the outlet sheet 6 are concentrically matched. The heating sheet 2 and the heater 3 are connected by metal deposition, the heating sheet 6 and the deformation sheet 5, and the deformation sheet 5 and the outlet sheet 6 are respectively sealed and connected by wafer bonding, and the base 1 and the heating sheet 2, the outlet sheet 6 and the valve cover 7 are sealed and connected by plane sealing glue. Therefore, the structure of the application is compact, and the miniaturization of the flow regulating valve can be realized.

[0057] Specifically, as shown in the figure Figure 4 The phase change material 4 is paraffin, which is used as the functional material of the entire regulating valve. The phase change volume expansion rate of paraffin is about 10%, which is a commonly used phase change volume expansion material. The paraffin is in a cylindrical shape and is placed in the deformation sheet groove 51. After the heating sheet 2 and the deformation sheet 5 are bonded, the paraffin is in surface contact with the heater 3, which increases the heat transfer efficiency.

[0058] Specifically, as shown in the figure Figure 1 , Figure 2 The outlet sheet 6 is made of a wafer, and the control space 61 and the flow hole 62 are both cylindrical spaces. In a preferred example, the outlet sheet 6 is made of a conventional silicon wafer, and the control space 61 and the flow hole 62 are two stepped circular through holes arranged along the axis. The control space 61 with a larger diameter is matched with the deformation sheet through hole 52 of the deformation sheet 5, and the gas enters the control space 61 of the outlet sheet 6 from the deformation sheet through hole 52, as shown in the figure Figure 3 When the starting end of the flow hole 62 with a smaller diameter is in close contact with the regulating diaphragm 53 of the deformation sheet 5, the gas flow regulating valve can be closed, thereby realizing the control of the flow.

[0059] Specifically, as shown in the figure Figure 1 The valve cover 7 is made of stainless steel, and the valve cover 7 is glued to the outlet sheet 6. The valve cover 7 has a valve cover through hole 71 arranged along the axis of the valve cover 7. The valve cover through hole 71 is a circular through hole. The valve cover through hole 71 serves as a gas downstream channel, and the gas enters the next component of the gas delivery through the valve cover 7.

[0060] The working principle of the application is as follows:

[0061] First, the heater 3 on the heating element 2 is energized. The heat generated by the heater 3 is transferred to the phase change material 4 through heat conduction. The phase change material 4 is heated and its temperature rises. When the temperature rises to the phase change temperature of the phase change material 4, the phase change material 4 undergoes a phase change, and its volume changes. Figure 3 As shown, the static pressure generated by the expanding phase change material 4 causes the adjusting diaphragm 53 on the deformable sheet 5 to deform, and this deformation causes... Figure 3 The cross-section of the gas channel in the middle is compared to Figure 2 The cross-sectional area of ​​the gas channel changes, thus restricting the gas flow into the flow orifice 62. A higher current in the heater 3 generates more heat, resulting in a larger volume of the phase change material 4 and the diaphragm 53 becoming closer to the flow orifice 62, thereby affecting the gas flow rate. Throughout the process, the gas flows through the base through-hole 11 of the base 1, successively through the gas channels of the heating element 2, the deformable element 5, and the outlet element 6, and finally enters the next component through the valve cover through-hole 71 in the valve cover 7. By adjusting the input power of the electrodes 8 at both ends of the heater 3, the heating power of the heater 3 can be adjusted, thereby controlling the deformation of the phase change material 4 and the deformable element 5, ultimately achieving gas flow rate regulation.

[0062] This application employs phase change materials (PCMs) as the driving medium. It utilizes the significant volume change of PCMs (such as paraffin wax or hydrogels) during their transition between solid and liquid states under different heating powers. A gas flow regulating valve adjusts the gas flow rate by controlling the volume change of the PCM. When heater 3 is operating, the temperature of the PCM gradually rises to its phase change temperature. Subsequently, the PCM undergoes a phase change process from a solid phase to a solid-liquid mixture and then back to a liquid phase. Different heating powers during the heating process correspond to different volume expansion rates. By adjusting the heating power of heater 3, different volume expansion rates of the PCM are obtained, thereby controlling the deflection of the regulating diaphragm 53 to change the cross-sectional area of ​​the gas channel, ultimately achieving flow regulation of the working gas.

[0063] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0064] The specific embodiments of the present application are described above. It needs to be understood that the present application is not limited to the above specific embodiments, and various changes or modifications can be made by those skilled in the art within the scope of the claims, which does not affect the essence of the present application. The embodiments of the present application and the features in the embodiments can be combined with each other at will without conflict.

Claims

1. Microelectromechanical system based phase change material driven gas flow regulating valve for satellite electric propulsion, characterized in that, It comprises a base (1), a heating sheet (2), a heater (3), a phase change material (4), a deformation sheet (5), an outlet sheet (6) and an electrode (8); The outlet sheet (6), the deformation sheet (5), the phase change material (4), the heater (3), the heating sheet (2) and the base (1) are sequentially connected; The base (1) is provided with a base through hole (11), the heating sheet (2) is provided with a heating sheet through hole (21), the deformation sheet (5) is provided with a deformation sheet groove (51), a deformation sheet through hole (52) and a corrugated diaphragm (53), and the outlet sheet (6) is provided with a control space (61) and a flow hole (62) in communication with the control space (61); The base through hole (11), the heating sheet through hole (21), the deformation sheet through hole (52), the control space (61) and the flow hole (62) are sequentially communicated; The deformation sheet (5) and the heating sheet (2) enclose the deformation sheet groove (51) into a sealed space, and the phase change material (4) is filled in the deformation sheet groove (51); The phase change material (4) and the heating sheet (2) are provided with the heater (3) therebetween; The two ends of the heater (3) are connected with the electrode (8) respectively; When the heater (3) is powered and heated, the phase change material (4) expands to drive the deformation sheet (5) to elastically deform towards the direction close to the flow hole (62); The heating sheet (2) adopts borosilicate glass material, and the heating sheet through hole (21) is two arc-shaped through holes which are axially symmetrical to each other; The heater (3) adopts platinum material, and the heater (3) is a serpentine structure formed by a plurality of parallel equidistant resistance wires connected in series; The heating sheet (2) and the heater (3) are connected by metal deposition; The deformation sheet (5) is made of silicon wafer, and the deformation sheet groove (51) is a cylindrical space; The deformation sheet through hole (52) is an arc-shaped through hole and the number is two; The two deformation sheet through holes (52) are symmetrically arranged on the two sides of the deformation sheet groove (51); The deformation sheet deformation part is a corrugated diaphragm (53).

2. The microelectromechanical system based phase change material actuated gas flow regulation valve for satellite electric propulsion according to claim 1, characterized in that, The base (1) adopts stainless steel material, and the base through hole (11) is a stepped through hole; The base (1) and the heating sheet (2) are glued.

3. The microelectromechanical system based phase change material actuated gas flow regulation valve for satellite electric propulsion according to claim 1, characterized in that, The phase change material (4) adopts paraffin.

4. The microelectromechanical system-based phase change material actuated gas flow regulation valve for satellite electric propulsion according to claim 1, characterized in that, The gas flow through the flow hole (62) is controlled at 0-2g / s.

5. The microelectromechanical system-based phase change material actuated gas flow regulation valve for satellite electric propulsion according to claim 1, characterized in that, The outlet sheet (6) is made of silicon wafer, and the control space (61) and the flow hole (62) are both cylindrical spaces.

6. The microelectromechanical system-based phase change material actuated gas flow regulation valve for satellite electric propulsion according to claim 1, characterized in that, It also comprises a valve cover (7) mounted on the outlet sheet (6); The valve cover (7) is provided with a valve cover through hole (71) in communication with the flow hole (62).

7. The microelectromechanical system based phase change material actuated gas flow regulation valve for satellite electric propulsion according to claim 6, characterized in that, The valve cover (7) and the outlet sheet (6) are glued; The valve cover (7) adopts stainless steel material.

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