Engine self-adaptive energy management and thermoelectric conversion system based on PID (Proportion Integration Differentiation) control

Abstract

The invention provides an engine self-adaptive energy management and thermoelectric conversion system based on PID control. The engine self-adaptive energy management and thermoelectric conversion system comprises a flat plate type loop heat pipe structure, a thermoelectric generator and a PID controller. The flat plate type loop heat pipe structure comprises a hot end module arranged in an interlayer of a nozzle throat shell at the rear section of the attitude and orbit control engine and a cold end module arranged at the front section of the attitude and orbit control engine. The thermoelectric generator is mounted between the liquid main pipe and the gas pipe; the PID controller is arranged in the spray pipe throat shell, and the temperature of the inner wall of the spray pipe throat shell serves as an input signal of the PID controller to control flow distribution of a coolant in the flat plate type loop heat pipe structure. According to the designed flat plate type loop heat pipe structure, a PID control system is introduced, the working condition of the flat plate type loop heat pipe structure in an attitude and orbit control engine can be improved through flow distribution adjustment, and the temperature of a spray pipe shell structure is kept stable; through the designed thermoelectric generator, stable potential can be generated by utilizing temperature difference, and electric energy is stored to provide energy.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid rocket engines, and particularly relates to an engine adaptive energy management and thermoelectric conversion system based on PID control. Background Art

[0002] The attitude and orbit control engine is a type of liquid rocket engine that uses liquid chemical substances as energy and working medium. It has the advantages of high specific impulse, multiple start capabilities, and a large thrust adjustment range, and can provide precise power for the attitude control and orbit control of spacecraft. The attitude and orbit control engine is a key propulsion system on spacecraft for achieving attitude control and orbit control. It generates a small thrust to precisely adjust the attitude (direction) and orbit (position) of the spacecraft to ensure the achievement of mission objectives. The thermal protection structure (TPS) is crucial for improving the performance of aircraft. With the development of aerospace technology, the heat dissipation problems faced by aerospace electronic equipment, weapon systems, engine accessories, and other parts are becoming increasingly severe. Developing efficient heat dissipation devices has become the research focus. The heat pipe technology has great application potential in the aerospace field due to its high heat transfer efficiency and compact structure. When the evaporation section of the heat pipe is heated, the liquid in the wick evaporates and vaporizes, and the vapor flows to the other end under the action of the pressure difference to release heat and condense into a liquid. The liquid then flows back to the evaporation section along the porous material under the action of capillary force, and the heat transfer is realized through this cycle.

[0003] Currently, the thermal protection structure (TPS) of traditional attitude and orbit control engines mostly adopts passive thermal protection methods, achieving thermal protection by selecting ablative materials or wrapping multi-layer insulation materials, and the cooling effect is limited. At the same time, the traditional thermal protection structure (TPS) has the defect of low efficiency in dealing with the problem of aerodynamic heat concentration and accumulation of hypersonic aircraft. When a hypersonic aircraft flies in the dense atmosphere, it will generate serious aerodynamic heating phenomena. The traditional TPS is difficult to efficiently handle these heats, making it impossible to achieve the comprehensive effects of thermal management and energy conservation. Summary of the Invention

[0004] The purpose of the invention is to solve the technical problem that the existing thermal protection structure of the attitude and orbit control engine has low heat dissipation efficiency for the nozzle throat and cannot achieve the comprehensive effects of thermal management and energy conservation, and provides an engine adaptive energy management and thermoelectric conversion system based on PID control.

[0005] To achieve the above purpose, the technical solution provided by the invention is:

[0006] An engine adaptive energy management and thermoelectric conversion system based on PID control is provided, which includes a flat loop heat pipe structure, a thermoelectric generator, and a PID controller with two connection ends; the flat loop heat pipe structure includes an evaporator and a condenser. The evaporator has a capillary structure and is arranged in the sandwich of the nozzle throat shell at the rear section of the attitude and orbit control engine. The condenser is arranged at the cold source inside the front section of the attitude and orbit control engine. The evaporator is connected to the cold end module through a gas pipe, a liquid main pipe, and a liquid return pipe. The working medium in the liquid main pipe absorbs heat and vaporizes in the evaporator, flows through the gas pipe to the condenser and condenses into a liquid state. The capillary structure inside the evaporator is used to make the liquid working medium flow from the condenser to the evaporator through the liquid main pipe, so as to transfer the heat of the nozzle throat to the front section of the attitude and orbit control engine, and cycle to complete the heat transfer; the thermoelectric generator is arranged at the front section of the attitude and orbit control engine and is installed between the liquid main pipe and the gas pipe to generate electric energy by using the temperature difference between the gas pipe and the liquid main pipe; the PID controller is arranged in the nozzle throat shell at the rear section of the attitude and orbit control engine. One connection end is electrically connected to a temperature sensor arranged on the inner wall of the nozzle throat shell at the rear section of the attitude and orbit control engine, and the other connection end is electrically connected to a valve arranged on the liquid return pipe. Taking the temperature of the inner wall of the nozzle throat shell monitored by the temperature sensor in real time as the input signal of the PID controller, the flow rate of the working medium flowing from the liquid main pipe to the liquid return pipe is controlled.

[0007] Further, the liquid return pipe and the liquid main pipe near the condenser are arranged on the inner wall of the shell of the attitude and orbit control engine; the liquid return pipe, the liquid main pipe, and the gas pipe located at the evaporator are in the nozzle throat shell of the attitude and orbit control engine.

[0008] Further, the gas pipe near the condenser is arranged close to the oxidizer delivery pipeline of the oxidizer storage tank.

[0009] Further, it also includes a power storage device, which is electrically connected to the thermoelectric generator, used to store the electric energy generated by the thermoelectric generator, and provide electric energy for the attitude control adjustment device of the attitude and orbit control engine.

[0010] Further, a pump for driving the working medium to flow into the evaporator is arranged on the liquid main pipe.

[0011] Further, the capillary structure is a wick.

[0012] Further, the condenser is installed on the outer wall of the oxidizer storage tank inside the attitude and orbit control engine.

[0013] The advantages of the present invention are:

[0014] 1. The working process of the flat loop heat pipe structure designed in the present invention introduces a PID control system, which can improve the working conditions of the flat loop heat pipe structure in the attitude and orbit control engine through flow distribution adjustment, suppress the temperature oscillation of the flat loop heat pipe structure, and maintain the temperature stability of the nozzle housing structure.

[0015] 2. When the flat loop heat pipe structure works in the attitude and orbit control engine, a temperature difference will be generated between the gas pipe and the liquid main pipe. Through the designed thermoelectric generator, a stable electric potential can be generated using the temperature difference and the electric energy can be stored to provide energy for subsequent attitude and orbit control adjustment.

[0016] 3. Compared with the heat dissipation structure of the traditional attitude and orbit control engine, the heat dissipation structure of the attitude and orbit control engine designed in the present invention introduces a thermal control and energy-saving integrated structure composed of a flat loop heat pipe structure, a thermoelectric generator, and a PID controller, which enhances the compact design of the structure and has both thermal protection and energy-saving effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Through the following description with reference to the drawings, the features and advantages of the present invention will become more easily understood. The drawings are not drawn to scale, and some features are enlarged or reduced to show the details of specific components. In the drawings:

[0018] Figure 1 is a schematic structural diagram of the engine adaptive energy management and thermoelectric conversion system of the present invention;

[0019] Figure 2 is a schematic diagram of the flat loop heat pipe installed in the sandwich of the nozzle throat housing of the engine of the present invention;

[0020] Figure 3 is a left view of the nozzle housing of the engine of the present invention;

[0021] Figure 4 is a main sectional view of the nozzle housing of the engine of the present invention;

[0022] In the figure: 1 - oxidizer storage tank; 2 - condenser; 3 - liquid main pipe; 4 - gas pipe; 5 - liquid return pipe; 6 - gear pump; 7 - evaporator; 8 - temperature sensor; 9 - PID controller; 10 - valve; 11 - thermoelectric generator; 12 - electricity storage device; 13 - attitude control adjustment device. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will be described in detail below with reference to the accompanying drawings by means of exemplary embodiments of the present invention. It should be noted that the following detailed description of the present invention is for illustrative purposes only and does not limit the present invention.

[0024] As Figure 1As shown in the figure, this embodiment provides an engine adaptive energy management and thermoelectric conversion system based on PID control, including a flat loop heat pipe structure, a thermoelectric generator 11, and a PID controller 9 with two connection ends.

[0025] As Figure 1 shown in the figure, the flat loop heat pipe structure includes an evaporator 7 and a condenser 2. The evaporator 7 has a capillary structure and is arranged in the sandwich of the nozzle throat shell at the rear section of the attitude and orbit control engine. The condenser 2 is arranged at the cold source inside the front section of the attitude and orbit control engine. The evaporator 7 is connected to the condenser 2 through a gas pipe 4, a liquid main pipe 3, and a liquid return pipe 5. A pump for driving the working medium to flow into the evaporator 7 is provided on the liquid return pipe 5. In this embodiment, the pump is a gear pump 6. The working medium in the liquid main pipe 3 absorbs heat and vaporizes in the evaporator 7, flows to the condenser 2 through the gas pipe 4 and condenses into a liquid state. The capillary structure inside the evaporator 7 is used to make the liquid working medium flow from the condenser 2 to the evaporator 7 through the liquid main pipe 3, so as to transfer the heat of the nozzle throat to the front section of the attitude and orbit control engine and complete the heat transfer by cyclic operation. Among them, the working medium is a coolant.

[0026] Specifically, the capillary structure is a wick, and the wick is arranged inside the evaporator 7. The condenser 2 is installed on the outer wall of the oxidizer tank 1 inside the attitude and orbit control engine, and the oxidizer tank 1 is the cold source at the front section of the attitude and orbit control engine. The wick can generate capillary force, and this structure can utilize the surface tension of the liquid to make the working medium return from the condenser 2 to the evaporator 7 and work in this cycle.

[0027] Among them, the liquid return pipe 5 and the liquid main pipe 3 near the condenser 2 are arranged on the inner wall of the shell of the attitude and orbit control engine; the liquid return pipe 5, the liquid main pipe 3, and the gas pipe 4 located at the evaporator 7 are located in the nozzle throat shell of the attitude and orbit control engine. The gas pipe 4 near the condenser 2 is arranged close to the oxidizer delivery pipeline of the oxidizer tank 1.

[0028] As Figure 1 shown in the figure, the thermoelectric generator 11 is arranged at the front section of the attitude and orbit control engine and is installed between the liquid main pipe 3 and the gas pipe 4 to generate electric energy by using the temperature difference between the gas pipe 4 and the liquid main pipe 3.

[0029] As Figure 1 、 2As shown in Figures 3 and 4, the PID controller 9 is arranged in the nozzle throat shell at the rear section of the attitude and orbit control engine. One connection end is connected to the temperature sensor 8 on the inner wall of the nozzle throat shell at the rear section of the attitude and orbit control engine, and the other connection end is connected to the valve 10 arranged on the liquid return pipe 5. Taking the temperature of the inner wall of the nozzle throat shell monitored in real time by the temperature sensor 8 as the input signal of the PID controller 9, the flow rate of the working medium flowing from the liquid main pipe 3 to the liquid return pipe 5 is controlled. Specifically, the valve 10 is a solenoid valve and is installed on the liquid return pipe 5 at the outlet of the evaporator 7.

[0030] When the temperature sensor 8 detects that the wall temperature of the inner wall of the nozzle throat shell is too high, the valve 10 of the liquid return pipe 5 is controlled by the PID controller 9 to adjust the flow rate distribution in the heat pipe and increase the coolant entering the evaporator 7. Specifically: by adjusting the opening degree of the valve 10 to change the resistance of the liquid return pipe 5, the control of the flow rate distribution can be realized. The valve 10 breaks the original flow balance through local resistance adjustment. The system with a flat-plate loop heat pipe structure will automatically adjust the flow velocity according to the new resistance distribution and finally reach a new pressure drop balance state to realize the adjustment of the flow rate distribution. Increasing the coolant entering the evaporator 7 can prevent the total pressure drop of the system from exceeding the maximum capillary force provided by the wick due to the too high heat source temperature, the temperature oscillation during the working process of the flat-plate loop heat pipe structure, and maintain the temperature stability of the nozzle shell structure.

[0031] As Figure 1 shown, the engine adaptive energy management and thermoelectric conversion system further includes a power storage device 12. The power storage device 12 is electrically connected to the thermoelectric generator 11 and is used to store the electric energy generated by the thermoelectric generator 11 and provide electric energy for the attitude control adjustment device 13 of the attitude and orbit control engine.

[0032] During operation, the gear pump 6 is first started. The coolant in the liquid main pipe 3 is driven by the gear pump 6 and flows into the evaporator 7. Part of the coolant is vaporized after being heated by the housing under the action of the wick in the evaporator 7. The vaporized gas flows back to the condenser 2 through the gas pipe 4 and becomes liquid again to continue participating in the heat pipe cycle. The remaining small part of the coolant flows directly back to the condenser 2 through the liquid return pipe 5. The temperature sensor 8 is connected to the PID controller 9, and the sensor signal serves as the input signal of the PID controller 9. When the housing temperature changes, the PID control system manages the coolant distribution in the flat-plate loop heat pipe structure cycle by adjusting the valve 10, suppresses the temperature oscillation of the heat pipe, and ensures normal operation. Among them, the coolant participating in the actual cooling process is the coolant except the liquid in the liquid return pipe 5. Part of the coolant in the liquid main pipe 3 becomes gas after absorbing heat in the evaporator 7, and the gas returns to the condenser 2 through the gas pipe 4 and liquefies. Therefore, when the housing temperature rises, the valve 10 should be closed slightly to allow less coolant to pass through the liquid return pipe 5, that is, more coolant participates in heat absorption and cooling in the evaporator 7. During the operation of the flat-plate loop heat pipe structure, the thermoelectric converter generates an electric potential using the temperature difference and stores the generated electric energy in the power storage device 12 to provide power input for the attitude control adjustment device 13.

[0033] In this embodiment, in order to improve the thermal protection performance and energy utilization efficiency of the attitude and orbit control engine, a thermal control and energy-saving device combining a flat-plate loop heat pipe structure based on PID control and a thermoelectric generator 11 is designed. Adding the PID controller 9 can stabilize the operation process of the flat-plate loop heat pipe, reduce the heat leakage of the evaporator 7 and the two-phase flow instability phenomenon in the heat pipe liquid storage chamber, and suppress the temperature oscillation of the heat pipe. The present invention completes heat transfer by arranging a flat-plate loop heat pipe structure inside the attitude and orbit control engine and in the sandwich layer of the nozzle throat housing, and arranges a closed-loop PID controller 9 in the sandwich layer of the nozzle throat housing to adjust the coolant flow rate in the heat pipe cycle according to different thermal conditions, and stabilizes parameters such as the thrust chamber housing temperature and thermal stress within a safe range. At the same time, a thermoelectric generator 11 is installed between the gas pipe 4 and the liquid pipe to generate an electric current using the temperature difference between the two. Energy is stored through the power storage device 12, and then power input is provided for the thrust vector adjustment device of the attitude and orbit control engine, and a compact integrated design of the thermal control and energy-saving system is carried out.

[0034] Finally, it should be noted that the features mentioned and / or shown in the above description of the exemplary embodiments of the present invention can be combined in the same or similar manner into one or more other embodiments, combined with the features in other embodiments or replace the corresponding features in other embodiments. The technical solutions obtained by such combination or replacement should also be regarded as being included within the protection scope of the present invention.

Claims

1. An engine adaptive energy management and thermoelectric conversion system based on PID control, characterized in that, Comprising: A flat loop heat pipe structure, including an evaporator (7) and a condenser (2). The evaporator (7) has a capillary structure and is arranged in the sandwich layer of the nozzle throat shell at the rear section of the attitude and orbit control engine. The condenser (2) is arranged at the cold source inside the front section of the attitude and orbit control engine. The evaporator (7) is communicated with the condenser (2) through a gas pipe (4), a liquid main pipe (3) and a liquid return pipe (5). The working medium in the liquid main pipe (3) absorbs heat and vaporizes in the evaporator (7), flows to the condenser (2) through the gas pipe (4) and condenses into a liquid state. The evaporator (7) has a capillary structure inside to enable the liquid working medium to flow from the condenser (2) to the evaporator (7) through the liquid main pipe (3), so as to transfer the heat of the nozzle throat to the front section of the attitude and orbit control engine, and cycle to complete the heat transfer; A thermoelectric generator (11), arranged at the front section of the attitude and orbit control engine and installed between the liquid main pipe (3) and the gas pipe (4), generating electric energy by using the temperature difference between the gas pipe (4) and the liquid main pipe (3); And a PID controller (9) with two connection ends, arranged in the nozzle throat shell at the rear section of the attitude and orbit control engine. One connection end is electrically connected to a temperature sensor (8) arranged on the inner wall of the nozzle throat shell at the rear section of the attitude and orbit control engine, and the other connection end is electrically connected to a valve (10) arranged on the liquid return pipe (5). Taking the temperature of the inner wall of the nozzle throat shell monitored by the temperature sensor (8) in real time as the input signal of the PID controller (9), it controls the flow rate of the working medium flowing from the liquid main pipe (3) to the liquid return pipe (5).

2. The engine adaptive energy management and thermoelectric conversion system based on PID control according to claim 1, characterized in that The liquid return pipe (5) and the liquid main pipe (3) near the condenser (2) are arranged on the inner wall of the shell of the attitude and orbit control engine; the liquid return pipe (5), the liquid main pipe (3) and the gas pipe (4) located at the evaporator (7) are in the nozzle throat shell of the attitude and orbit control engine.

3. The engine adaptive energy management and thermoelectric conversion system based on PID control according to claim 2, wherein, The gas pipe (4) near the condenser (2) is arranged close to the oxidizer delivery pipeline of the oxidizer storage tank (1).

4. The engine adaptive energy management and thermoelectric conversion system based on PID control according to claim 1, characterized in that, It further includes a power storage device (12), and the power storage device (12) is electrically connected to the thermoelectric generator (11) for storing the electric energy generated by the thermoelectric generator (11) and providing electric energy for the attitude control adjustment device (13) of the attitude and orbit control engine.

5. The engine adaptive energy management and thermoelectric conversion system based on PID control according to claim 1, characterized in that A pump for driving the working medium to flow into the evaporator (7) is arranged on the liquid return pipe (5).

6. The engine adaptive energy management and thermoelectric conversion system based on PID control according to claim 1, wherein The capillary structure is a wick.

7. The engine adaptive energy management and thermoelectric conversion system based on PID control according to claim 1, characterized in that, The condenser (2) is installed on the outer wall of the oxidizer storage tank (1) inside the attitude and orbit control engine.

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