1. The utility model provides a to wireless self-power temperature measurement system for aeroengine, its characterized in that, the system includes temperature measurement terminal, energy supply module and energy management module, energy supply module is with energy input to energy management module, energy management module is with energy input to temperature measurement terminal, wireless transmission between measuring terminal and the Zigbee coordinator node, Zigbee coordinator node is with signal transmission to the host computer.

2. The system of claim 1, wherein the energy management module includes a battery module and a charging and discharging conversion circuit, the temperature measurement terminal includes a K-type thermocouple stack and a Zigbee terminal module, the energy supply module includes a thermoelectric generation piece, the thermoelectric generation piece inputs energy into the charging and discharging conversion circuit, the charging and discharging conversion circuit performs energy conversion with the battery module, the charging and discharging conversion circuit inputs energy into the Zigbee terminal module, the K-type thermocouple stack transmits the collected voltage pattern to the Zigbee terminal module, and the Zigbee terminal module wirelessly transmits the voltage pattern to the Zigbee coordinator node.

3. The wireless self-powered temperature measuring system for the aircraft engine according to claim 2, wherein the charge-discharge conversion circuit comprises an interface P1, a terminal 1 of the interface P1 is respectively connected with one end of a capacitor C3, one end of a capacitor C6, a terminal 4 of a chip U2, a terminal 5 of a chip U2, and a working voltage VCC with one end of an inductor L1, the other end of the inductor L1 is respectively connected with a terminal 1 of a chip U2 and an anode of a diode D1, a cathode of the diode D1 is respectively connected with one end of a resistor R2, one end of a capacitor C9, one end of a capacitor C24, one end of a capacitor C11, and one end of a capacitor C7 are respectively connected with an anode of a diode D469, a cathode of the diode D1 is respectively connected with one end of a power supply 1, one end of a capacitor C8, one end of a capacitor C4, a terminal 1 of a chip U1, and a terminal 3 of a chip 686u 1, and a terminal 1 of the capacitor BT 72 are respectively connected with an end of the terminal 1 and a terminal of the chip U2, One end of a capacitor C5, one end of a resistor R1, the working voltage of 3.3V and the No. 1 end of an interface P1;

the No. 5 end of the chip U2 is respectively connected with the other end of the capacitor R2 and one end of the capacitor R3, and the other end of the capacitor R1 is connected with the anode of the light-emitting diode D3;

the No. 2 end of the interface P1 is respectively connected with the other end of the capacitor C3, the other end of the capacitor C6, the No. 2 end of the chip U2, the other end of the capacitor R3, the other end of the capacitor C9, the other end of the capacitor C10, the other end of the capacitor C11, the other end of the capacitor C7, the other end of the power supply BT1, the other end of the capacitor C8, the other end of the capacitor C4, the No. 2 end of the chip U1, the other end of the capacitor C1, the other end of the capacitor C2, the other end of the capacitor C5, the cathode of the light emitting diode D3 and the No. 2 end of the interface P2.

4. The test method for the wireless self-powered temperature measurement system of the aircraft engine according to claim 1, characterized in that the test method comprises the following steps:

step 1: the heating plate and the water cooling plate are opened to work, so that the temperature difference of 150-200 ℃ is formed between the upper surface and the lower surface of the temperature difference power generation sheet;

step 2: connecting the thermoelectric power generation piece in the step 1 with a charge-discharge conversion circuit, and inserting a storage battery on the charge-discharge conversion circuit;

and step 3: connecting the charge-discharge conversion circuit in the step 2 with a zigbee terminal working node;

and 4, step 4: and (4) wirelessly connecting the zigbee terminal working node in the step (3) with a zigbee coordinator node, and displaying a serial port receiving interface through an upper computer.

Background

In traditional aerospace vehicles, most information transmission is guaranteed by a cable measurement and control system, but along with the continuous improvement of the performance of the aircraft, the control requirements are rich, and the number of the existing sensors cannot meet the measurement requirements under complex control. Taking an aircraft core component, namely an aircraft engine, as an example, an automatic measurement and control system of the aircraft engine must have two characteristics, namely, the first, the automatic measurement and control system of the aircraft engine needs to have stronger logical judgment capability and operation processing capability; secondly, aviation measurement and control have higher requirements on the test speed and the test accuracy. To meet the speed and accuracy of the test, a sufficient number of site sensors must be populated. However, too many measurement sensors inevitably lead to an increase in the number of cables inside the aircraft, which inevitably entails two problems for the aircraft, on the one hand, an increase in the own weight of the aircraft and a reduction in payload. On the other hand, in a limited space, under the condition of ensuring safety and stability, the number of wiring is limited, the limited number of measurement channels cannot provide a basis for high-performance control of the engine, and a bottleneck is caused to the improvement of the control performance of the engine in the future.

How to reduce the use of cables to the maximum extent while ensuring and even increasing the number of original detection nodes becomes a key problem for improving the performance of the aircraft.

Disclosure of Invention

The invention provides a wireless self-powered temperature measurement system for an aircraft engine and a measurement method thereof, which solve the energy supply problem of a wireless sensor node and widen the maximum number of temperature measurement nodes in the traditional limited temperature measurement mode.

The invention is realized by the following technical scheme:

the utility model provides a wireless self-power temperature measurement system for aeroengine, the system includes temperature measurement terminal, energy supply module and energy management module, energy supply module is with energy input to energy management module, energy management module is with energy input to temperature measurement terminal, wireless transmission between measuring terminal and the Zigbee coordinator node, Zigbee coordinator node is with signal transmission to the host computer.

Further, the energy management module comprises a storage battery module and a charging and discharging conversion circuit, the temperature measuring terminal comprises a K-type thermocouple stack and a Zigbee terminal module, the energy supply module comprises a thermoelectric generation piece, the thermoelectric generation piece inputs energy into the charging and discharging conversion circuit, the charging and discharging conversion circuit performs energy conversion with the storage battery module, the charging and discharging conversion circuit inputs the energy into the Zigbee terminal module, the K-type thermocouple stack transmits the acquired voltage type to the Zigbee terminal module, and the Zigbee terminal module and the Zigbee coordinator node perform wireless transmission.

Furthermore, the charge-discharge conversion circuit comprises an interface P1, wherein the terminal No. 1 of the interface P1 is respectively connected with one end of a capacitor C3, one end of a capacitor C6, the terminal No. 4 of a chip U2, the terminal No. 5 of a chip U2, the working voltage VCC is connected with one end of an inductor L1, the other end of the inductor L1 is respectively connected with the No. 1 terminal of the chip U2 and the anode of the diode D1, the cathode of the diode D1 is respectively connected with one end of the resistor R2, one end of the capacitor C9, one end of the capacitor C10, one end of the capacitor C11 and one end of the capacitor C7, and the anode of the diode D2, the cathode of the diode D1 is respectively connected with one end of a power supply BT1, one end of a capacitor C8, one end of a capacitor C4, the No. 1 end of a chip U1 and the No. 3 end of a chip U1, the No. 5 end of the chip U1 is respectively connected with one end of a capacitor C2, one end of a capacitor C5, one end of a resistor R1, the working voltage of 3.3V and the No. 1 end of an interface P1;

the No. 5 end of the chip U2 is respectively connected with the other end of the capacitor R2 and one end of the capacitor R3, and the other end of the capacitor R1 is connected with the anode of the light-emitting diode D3;

the No. 2 end of the interface P1 is respectively connected with the other end of the capacitor C3, the other end of the capacitor C6, the No. 2 end of the chip U2, the other end of the capacitor R3, the other end of the capacitor C9, the other end of the capacitor C10, the other end of the capacitor C11, the other end of the capacitor C7, the other end of the power supply BT1, the other end of the capacitor C8, the other end of the capacitor C4, the No. 2 end of the chip U1, the other end of the capacitor C1, the other end of the capacitor C2, the other end of the capacitor C5, the cathode of the light emitting diode D3 and the No. 2 end of the interface P2.

A testing method for a wireless self-powered temperature measurement system of an aircraft engine comprises the following steps:

step 1: the heating plate and the water cooling plate are opened to work, and the temperature difference of 150-200 ℃ is formed between the upper surface and the lower surface of the temperature difference power generation plate;

step 2: connecting the thermoelectric power generation piece in the step 1 with a charge-discharge conversion circuit, and inserting a storage battery on the charge-discharge conversion circuit;

and step 3: connecting the charge-discharge conversion circuit in the step 2 with a zigbee terminal working node;

and 4, step 4: and (4) wirelessly connecting the zigbee terminal working node in the step (3) with a zigbee coordinator node, and displaying a serial port receiving interface through an upper computer.

The invention has the beneficial effects that:

the invention adopts the zigbee module with low power consumption as the wireless transmitting terminal, and utilizes the mode of the zigbee with ultra-low power consumption dormancy and self-networking to expand and design the whole self-powered wireless stability measuring node. Compared with the temperature measuring node of the original wireless sensor, on one hand, the temperature measuring range is widened, the temperature measuring module with the highest measurable temperature of about 100 ℃ is widened to the condition that the temperature measuring module with the highest measurable temperature of about 1000 ℃ is enlarged when the engine works, and on the other hand, the huge waste heat existing in the aero-engine during working is utilized to supply power for the whole wireless temperature measuring terminal sensor through the thermoelectric effect of the thermoelectric generation piece. Compared with the prior wired measurement mode, the invention reduces the use of cables in the whole process from information transmission to energy supply and also provides a space for increasing the number of measurement nodes which can be accessed by the whole engine.

Drawings

Fig. 1 is a block diagram of the terminal node components of the present invention.

FIG. 2 is a schematic representation of an embodiment of the present invention.

FIG. 3 is a test chart of the present invention.

FIG. 4 is a comparison of the collected voltage signal of the present invention with the actual thermocouple output voltage signal.

Fig. 5 is a charge-discharge conversion circuit of the present invention.

Fig. 6 is a concrete graph of the capacity of the battery of the present invention.

Fig. 7 is a schematic diagram of a serial port receiving interface of the present invention.

FIG. 8 is a diagram showing the specific voltage variation of the charging current of the storage battery when the zigbee works according to the invention.

FIG. 9 shows the voltage change of the battery when the thermoelectric generation element of the present invention stops supplying power.

FIG. 10 is a graph showing the output voltage and the temperature variation of the high temperature side of a 20X 20mm power generation sheet according to the present invention

FIG. 11 is a graph showing the internal resistance and the temperature change at the high temperature side of a 20X 20mm power generation sheet according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The utility model provides a wireless self-power temperature measurement system for aeroengine, the system includes temperature measurement terminal, energy supply module and energy management module, energy supply module is with energy input to energy management module, energy management module is with energy input to temperature measurement terminal, wireless transmission between measuring terminal and the Zigbee coordinator node, Zigbee coordinator node is with signal transmission to the host computer.

And the temperature measuring terminal consists of a K-type thermocouple stack and a zigbee temperature measuring terminal node. The thermocouple selecting stack is formed by connecting ten K-type thermocouples with the temperature measuring range of 0-1050 ℃ in series. When the thermocouple senses specific temperature, potential difference can be generated due to the thermoelectric effect, and thermocouple output signals acquired from the positive side and the negative side of the thermocouple stack and amplified by 10 times are transmitted to a P06 acquisition voltage port of a terminal node through signal wires by connecting the thermocouples in series. The Zigbee temperature measuring terminal mainly comprises a CC2530 chip and a bottom plate, wherein E18-MS1-PCB test plate hardware manufactured by hundred million and Tet company is selected. The ADC acquisition voltage code is burned into the test board hardware through a Smarf04EB simulator. The temperature measuring terminal realizes the following functions through specific acquisition codes: (1) collecting voltage signals from the thermocouple stack through a collection port P06, and (2) sending voltage data to a coordinator node connected with a PC (personal computer) in the identity of a terminal through a zigbee network where the voltage data are located.

The energy supply module generates power by utilizing the temperature difference between the inner wall surface of an aircraft engine and the incoming flow of an outer duct when the aircraft engine works, a high-temperature resistant power generation sheet made of bismuth telluride and having the model number of SP1848-27145 is selected, and the size of the power generation sheet is selected to be 20mm multiplied by 6mm in consideration of the actual requirement of carrying the aircraft engine. When the temperature difference between the two ends of the cold and hot surfaces is more than 150 ℃, the power generation sheet can stably output more than 2V voltage to supply energy for the wireless temperature measurement terminal node and the storage battery in the energy management system.

The energy management module boosts a voltage signal of 2-3V input by the temperature difference power generation piece to 5V which is stable and serves as a power supply, under normal work, the power supply charges a storage battery with charging current of about 10ma while ensuring the operation of the zigbee measurement terminal, and when the temperature difference power supply side stops supplying power, the energy management module supplies power to the zigbee terminal node through the connected storage battery. The energy supply is realized by firstly boosting the power supply voltage through the SX1308 module, then avoiding the influence of the power utilization side on the power supply side by arranging an isolation diode, and finally converting the voltage of about 4.5V into 3.3V for stable output by utilizing an RT9193 chip to supply power for the zigbee.

Further, the energy management module comprises a storage battery module and a charging and discharging conversion circuit, the temperature measuring terminal comprises a K-type thermocouple stack and a Zigbee terminal module, the energy supply module comprises a thermoelectric generation piece, the thermoelectric generation piece inputs energy into the charging and discharging conversion circuit, the charging and discharging conversion circuit performs energy conversion with the storage battery module, the charging and discharging conversion circuit inputs the energy into the Zigbee terminal module, the K-type thermocouple stack transmits the acquired voltage type to the Zigbee terminal module, and the Zigbee terminal module and the Zigbee coordinator node perform wireless transmission.

Furthermore, the charge-discharge conversion circuit comprises an interface P1, wherein the terminal No. 1 of the interface P1 is respectively connected with one end of a capacitor C3, one end of a capacitor C6, the terminal No. 4 of a chip U2, the terminal No. 5 of a chip U2, the working voltage VCC is connected with one end of an inductor L1, the other end of the inductor L1 is respectively connected with the No. 1 terminal of the chip U2 and the anode of the diode D1, the cathode of the diode D1 is respectively connected with one end of the resistor R2, one end of the capacitor C9, one end of the capacitor C10, one end of the capacitor C11 and one end of the capacitor C7, and the anode of the diode D2, the cathode of the diode D1 is respectively connected with one end of a power supply BT1, one end of a capacitor C8, one end of a capacitor C4, the No. 1 end of a chip U1 and the No. 3 end of a chip U1, the No. 5 end of the chip U1 is respectively connected with one end of a capacitor C2, one end of a capacitor C5, one end of a resistor R1, the working voltage of 3.3V and the No. 1 end of an interface P1;

the No. 5 end of the chip U2 is respectively connected with the other end of the capacitor R2 and one end of the capacitor R3, and the other end of the capacitor R1 is connected with the anode of the light-emitting diode D3;

the No. 2 end of the interface P1 is respectively connected with the other end of the capacitor C3, the other end of the capacitor C6, the No. 2 end of the chip U2, the other end of the capacitor R3, the other end of the capacitor C9, the other end of the capacitor C10, the other end of the capacitor C11, the other end of the capacitor C7, the other end of the power supply BT1, the other end of the capacitor C8, the other end of the capacitor C4, the No. 2 end of the chip U1, the other end of the capacitor C1, the other end of the capacitor C2, the other end of the capacitor C5, the cathode of the light emitting diode D3 and the No. 2 end of the interface P2.

A testing method for a wireless self-powered temperature measurement system of an aircraft engine comprises the following steps:

step 1: the heating plate and the water cooling plate are opened to work, and the temperature difference of 150-200 ℃ is formed between the upper surface and the lower surface of the temperature difference power generation plate;

step 2: connecting the thermoelectric power generation piece in the step 1 with a charge-discharge conversion circuit, and inserting a storage battery on the charge-discharge conversion circuit;

and step 3: connecting the charge-discharge conversion circuit in the step 2 with a zigbee terminal working node;

and 4, step 4: and (4) wirelessly connecting the zigbee terminal working node in the step (3) with a zigbee coordinator node, and displaying a serial port receiving interface through an upper computer.

In the specific working process of the aero-engine, as the combustion chamber of the aero-engine can emit a large amount of heat during working, the core temperature inside the combustion chamber can reach 1300 ℃, and the temperature difference between the combustion chamber and the outer duct is large. Therefore, a large amount of heat which is difficult to utilize is generated on the wall surface of the engine, and the heat does not have a great effect on power increase of the engine, influences are brought to normal operation of the engine, and problems are brought to cooling of the engine. Therefore, the construction requirement of the self-powered wireless temperature measurement system is to provide temperature difference for the temperature difference power generation sheet by utilizing waste heat in the working process of the engine. According to relevant data research, when the temperature difference of the high-temperature side and the low-temperature side is about 180 ℃, the voltage of the temperature difference power generation sheet made of 40 mm-40 mm bismuth telluride can reach about 2.5V, so that the temperature difference power generation sensor utilizes the actual condition of high temperature of the wall surface to supply energy to the sensor.

The heating plate and the water cooling plate are used for replacing a high-temperature heat source and a low-temperature cooling source.

In order to ensure the normal operation of the engine, a storage battery module is prepared in a node of the system, and a specific curve of the capacity of the storage battery is given according to the specific power consumption of a zigbee acquisition module, as shown in fig. 6.

And (3) starting a zigbee terminal module to place the temperature measuring thermocouple stack on a temperature plane to be measured to ensure that ten temperature measuring nodes are in full contact with the plane to be measured, wherein the temperature difference of more than 150 ℃ exists between the two sides of the temperature difference generating piece or certain electric quantity exists in the storage battery.

And when the zigbee module work indicator lamp is turned on, the upper computer serial port receiving interface is turned on, and the coordinator module is connected through Usb, so that the specific voltage value converted by the temperature to be measured can be read on the serial port interface.

Fig. 8 and 9 demonstrate that the design of the entire thermoelectric power supply system meets the power supply requirements of the wireless measurement sensor.

By measuring and calculating the highest current of the zigbee terminal during working, the maximum current of the zigbee can be obtained from the peak change of the zigbee when the zigbee terminal sends a packet, the current is about 36mA, the peak maximum power is 0.1188w, and the circuit management module as a conversion circuit inevitably introduces certain loss during voltage conversion. When the external circuit management module is switched, in order to indicate the power supply to work, a circuit indicator lamp also needs to be introduced, extra power consumption is added to the whole system, here, in order to increase allowance to ensure the system to work, the efficiency factor of normal power supply is about 0.8, then the large power consumption needed by the zigbee side is 0.1485W, in combination with the actual starting process of the engine, the self-powered wireless measurement sensor should run before the engine works, considering that the starting time of the civil engine is 2-3min, the military engine is generally faster, here, in order to widen the margin, the preposed working time (namely the time when the power generating sheet does not supply power) is 10min, in combination with the actual wall temperature requirement of the aircraft engine, the minimum working time of the engine is 10min, the engine is stopped, and the chargeable cooling time when the wall surface is higher than 200 ℃ is 20min, the output power W of the power generating sheet should meet:

(W-0.1485)×10+20W＞10×0.1485 (1)

it can be understood that W should be greater than 0.099W, and specific choices of the thermoelectric power generation sheet are given below the maximum output power of the power generation sheet.

The thermoelectric power generation sheet potential is selected to select a proper power generation sheet material and the area of the power generation sheet, and important parameters for evaluating the thermoelectric performance of the power generation sheet, one is a Seebeck coefficient alpha for measuring voltage output, the unit of the Seebeck coefficient alpha is v/K, the size of the thermoelectric effect of the thermoelectric material is represented, and according to the Seebeck effect, the output voltage value of the thermoelectric material meets the following formula:

because the maximum temperature of the thermoelectric generation piece is 220 ℃, the delta T is 150 in consideration of the temperature limit of the power generation piece and the stable temperature difference which can be actually provided. According to the rule that the output power changes along with the load resistance, along with the increase of the load resistance, when the load resistance is equal to the internal resistance, the maximum output is taken, so that the resistance values of the load resistance and the internal resistance are equal, and an inequality can be obtained:

according to the actual resistance value of the power generating sheet, r is 5, the total alpha coefficient of the power generating sheet is larger than 0.0094, and after the total Seebeck coefficient of the power generating sheet is determined, the optimal value Z influencing the actual efficiency of the power generating sheet is also considered.

Taking the actual working efficiency of the thermoelectric generation piece as eta, the eta can be obtained:

p is the actual output power of the power generation sheet, the formula is mentioned above, Q always comprises the heat conduction quantity of the thermoelectric power generation sheet from the hot end to the cold end, the heat quantity generated by the Peltier effect of the thermoelectric power generation sheet at the hot end and the difference of the Joule heat generated by the current, and the difference can be obtained by calculation

Wherein T is_aFor the temperature of the hot end of the power generating sheet, T_bThe total heat conductivity coefficient of the lambda semiconductor device is the cold end temperature of the power generation sheet, m is the ratio of the load resistance to the internal resistance, and r is the internal resistance of the power generation sheet. To better illustrate the factors that affect efficiency, the thermoelectric figure of merit Z, defined herein, is:

Z＝α²/λr (6)

since the thermoelectric efficiency of the power generation sheet increases with the increase in the figure of merit Z by substituting the figure of merit Z with α as the seebeck coefficient, λ as the thermal conductivity, and r as the internal resistance of the power generation sheet, the power generation sheet having a large Z value should be selected together with the large seebeck coefficient power generation sheet in order to improve the thermoelectric efficiency of the power generation sheet. In addition, in consideration of the area requirement in integration, the power generating sheet with the area of 30 × 30mm or less is required as much as possible.

Through the conditions, a thermoelectric power generation piece of the model SP1848 series is selected, the area of the thermoelectric power generation piece is 20 multiplied by 20mm and 30 multiplied by 30mm, and the open circuit voltage and the output power of the power generation piece when the load resistance is 10 ohms under different temperature differences are tested. As shown in fig. 2.

The power generation piece body testing method comprises the steps of selecting an electric heating temperature controller to control the temperature of a heating plate, controlling the cold end temperature of the thermoelectric power generation piece by a water cooling piece, measuring open-circuit voltage by a voltmeter, and in the experimental process, through a water cooling device, the low-temperature side temperature is always about 20 ℃, and the upper graph is a specific experimental device graph during power generation piece testing.

From the experimental data in fig. 10-11, it can be known that when the output voltage increases with the increasing temperature, and the temperature is 190 ℃ at the high temperature side, that is, the temperature difference is 170 ℃, the output voltage of the power generation sheet is 2.6V, and according to the experimental data curve, the seebeck coefficient of the power generation sheet with 20 × 20mm is 0.0153, which meets the specific requirements of the power generation sheet. And calculating the output voltage and the output current at different temperatures to obtain the internal resistance of the capacitor to be about 5 omega.