阅读说明：本技术 一种用于推力室周向均布单孔流量自动同步检测装置 (Be used for thrust chamber circumference equipartition haplopore flow automatic synchronization detection device ) 是由 钟玮 彭中伟 姬西峰 任艳 刘婷 苏晨 教传军 于 2020-11-23 设计创作，主要内容包括：本发明公开了一种推力室周向均布单孔流量自动同步检测装置,由试验台架体、升降机构和产品安装平台组成；升降机构安装在试验台架体上方的支撑板一侧,在升降机构上安装产品安装平台,通过旋转手轮带动丝杠转动来调整产品安装平台的高度；在产品安装平台上安装有工装；试验台架体内部底端设置有水箱,大固定板和小固定板,在水箱中央设置有导水桶、收水盘和收集盘,在大固定板上固定有标准U型体积管,标准U型体积管上连接有液位光电传感器；收集盘中间为12等份的收集装置,收集装置中央安装有螺纹连接式导流管；在收集盘每一等份的边缘有排水嘴；试验台架体上方的支撑板上还安装有机架；机架四面安装有机玻璃防水板；在试验台架体内还设有换向气缸。(The invention discloses an automatic synchronous detection device for single-hole flow uniformly distributed in the circumferential direction of a thrust chamber, which consists of a test bed frame body, a lifting mechanism and a product mounting platform; the lifting mechanism is arranged on one side of the supporting plate above the test bed frame body, a product mounting platform is arranged on the lifting mechanism, and the height of the product mounting platform is adjusted by rotating the hand wheel to drive the screw to rotate; a tool is arranged on the product mounting platform; the bottom end of the inner part of the test bed body is provided with a water tank, a large fixing plate and a small fixing plate, the center of the water tank is provided with a water guide barrel, a water collecting tray and a collecting tray, a standard U-shaped volume pipe is fixed on the large fixing plate, and a liquid level photoelectric sensor is connected on the standard U-shaped volume pipe; the middle of the collecting tray is provided with 12 equal parts of collecting devices, and the centers of the collecting devices are provided with flow guide pipes in threaded connection; a drain nozzle is arranged at the edge of each equal part of the collecting tray; a rack is also arranged on the supporting plate above the test bed frame body; organic glass waterproof plates are arranged on four sides of the frame; a reversing cylinder is also arranged in the test bed body.)

1. A single-hole flow automatic synchronous detection device with a thrust chamber uniformly distributed in the circumferential direction is characterized by comprising a test bed frame body (4), a lifting mechanism (3) and a product mounting platform (24); wherein:

the lifting mechanism (3) is arranged on one side of a supporting plate (29) above the test bed frame body (4), a product mounting platform (24) is arranged on the lifting mechanism (3), and the height of the product mounting platform (24) is adjusted by rotating a hand wheel (22) to drive a lead screw (23) to rotate; a tool (25) for fixing and sealing a product is arranged on the product mounting platform (24), and a pressure measuring channel is reserved on the tool (25);

the water tank (21) is arranged at the bottom end inside the test bed frame body (4), the large fixing plate (8) and the small fixing plate (9) are installed inside the test bed frame body, the large fixing plate (8) is installed on the supporting angle steel (15), and the supporting angle steel (15) is fixed with the test bed frame body (4) through bolts; the large fixing plate (8) and the small fixing plate (9) are fixedly connected through a double-end stud (14);

a water guide barrel (17) is arranged in the center of a water tank (21), a water collecting tray (6) is arranged above the water guide barrel (17), a collecting tray (5) is arranged above the water collecting tray (6), a water return port and a water return hose (26) which are connected with the water collecting tray (6) are arranged at the bottom of the collecting tray (5), a water receiving nozzle (10) penetrating through a large fixing plate (8) is arranged at the edge of the collecting tray (5), a standard U-shaped volume pipe (2) is fixed on the large fixing plate (8), and a liquid level photoelectric sensor (20) is connected on the standard U-shaped volume pipe (2); the water receiving nozzle (10) and the standard U-shaped volume pipe (2) are fixed on a standard U-shaped volume pipe bracket (27) on the small fixing plate (9); a pipeline connected with the water receiving nozzle (10) and the standard U-shaped volume pipe (2) is connected with a test tube water return hose (28) through a direct-acting electromagnetic valve (19), and the test tube water return hose (28) is communicated with a water tank (21);

the middle of the collecting tray (5) is provided with 12 equal parts of collecting devices (1), and the center of each collecting device (1) is provided with a threaded connection type guide pipe (11); a drain nozzle (16) is arranged at the edge of each equal part of the collecting tray (5); the thread-connected guide pipe (11) is provided with a thrust bearing (12), and the thread-connected guide pipe (11) penetrates through the support plate (29), the collection disc (5) and the water collection disc (6) to be connected with the water tank (21);

a rack (13) is also arranged on the support plate (29) above the test bed frame body (4); organic glass waterproof plates (7) are arranged on four sides of the frame (13);

still be equipped with switching-over cylinder (18) in test bench support body (4), switching-over cylinder (18) promote collecting tray (5), make water receiving nozzle (10) and collection device (1) drain nozzle (16) axis coincidence, make collection device (1) rivers access to standard U type volume pipe (2), accomplish test water and collect.

2. The automatic synchronous detection device for the flows of the single holes uniformly distributed in the circumferential direction of the thrust chamber as claimed in claim 1, wherein the reversing cylinder (18) is positioned at the joint of the inside of the test bed frame and the upper left of the support plate (29).

3. The thrust chamber circumferentially equispaced single-hole flow automatic synchronous detection device of claim 1, wherein the standard U-shaped volume tube (2) is machined from an organic glass tube.

4. The thrust chamber single-hole flow automatic synchronous detection device uniformly distributed in the circumferential direction of claim 1, wherein the water collecting disc (6) is connected with the water guide barrel (17) through welding, and the water guide barrel (17) is connected with the water tank (21) through welding.

Technical Field

The invention belongs to the technical field of flow measurement, relates to a flow measurement device, and particularly relates to a device for automatically and synchronously detecting the flow of a single hole uniformly distributed in the circumferential direction of a thrust chamber.

Background

At present, when flow measurement is carried out on single small holes which are uniformly distributed in the circumferential direction of a thrust chamber, the traditional technological method is a manual hole-by-hole timing weighing method. During testing, a tested product is firstly butted with a testing system, after the flow at an inlet is manually adjusted to reach a rated working condition, a tester manually receives the jet flow of each hole, and simultaneously, a stopwatch is operated to time, the collected single-hole jet flow is weighed by an electronic scale to obtain a collection mass, and the flow of each hole is obtained through calculation according to the collection mass and the jet flow time. The flow needs to be measured hole by hole in the whole test process, and the whole test time is prolonged; manual collection is adopted, the requirement for skilled reading of the manual is high, the measurement error is increased, the measurement times are required to be increased to eliminate the error influence, and the test time is also increased; the target of receiving all the holes simultaneously cannot be realized due to the lack of a test platform; and with the rapid increase of the batch production quantity of the shaped products, the overall test time is long, the measurement error is large, the test efficiency is low, and the manual labor is insufficient, so that the traditional method can not meet the test requirements of the products.

Disclosure of Invention

In view of the above-mentioned drawbacks or deficiencies in the prior art, an object of the present invention is to provide an automatic synchronous detection device for single-hole flow uniformly distributed in the circumferential direction of a thrust chamber, which can automatically switch the state of a water receiving device, automatically drain water, accurately collect single-hole flow, and simultaneously perform multiple hole sites according to test input conditions, thereby effectively improving test efficiency, improving test data accuracy and stability, reducing operation intensity, and reducing measurement errors.

In order to realize the task, the invention adopts the following technical solution:

a single-hole flow automatic synchronous detection device with a thrust chamber uniformly distributed in the circumferential direction is characterized by comprising a test bed frame body, a lifting mechanism and a product mounting platform; wherein:

the lifting mechanism is arranged on one side of the supporting plate above the test bed frame body, a product mounting platform is arranged on the lifting mechanism, and the height of the product mounting platform is adjusted by rotating the hand wheel to drive the screw to rotate; a tool for fixing and sealing a product is installed on the product installation platform, and a pressure measurement channel is reserved on the tool;

the bottom end of the inner part of the test bed body is provided with a water tank, a large fixing plate and a small fixing plate are arranged in the test bed body, the large fixing plate is arranged on a supporting angle steel, and the supporting angle steel is fixed with the test bed body through a bolt; the large fixing plate and the small fixing plate are fixedly connected through a double-end stud;

a water guide barrel is arranged in the center of the water tank, a water collecting disc is arranged above the water guide barrel, a collecting disc is arranged above the water collecting disc, the bottom of the collecting disc is also provided with a water return port and a water return hose which are connected with the water collecting disc, the edge of the collecting disc is provided with a water receiving nozzle which penetrates through a large fixing plate, a standard U-shaped volume pipe is fixed on the large fixing plate, and a liquid level photoelectric sensor is connected on the standard U-shaped volume pipe; the water receiving nozzle and the standard U-shaped volume pipe are fixed on a standard U-shaped volume pipe bracket on the small fixing plate; a pipeline connected with the water receiving nozzle and the standard U-shaped integral pipe is connected with a test tube water return hose through a direct-acting electromagnetic valve, and the test tube water return hose is communicated with a water tank;

the middle of the collecting tray is provided with 12 equal parts of collecting devices, and the centers of the collecting devices are provided with flow guide pipes in threaded connection; a drainage nozzle is arranged at the edge of each equal part of the collecting tray; the threaded connection type guide pipe is provided with a thrust bearing and penetrates through the support plate, the collection disc and the water collection disc to be connected with the water tank;

a rack is also arranged on the supporting plate above the test bed frame body; organic glass waterproof plates are arranged on four sides of the frame;

still be equipped with the switching-over cylinder in the test bench is internal, and the switching-over cylinder promotes the collection dish, makes water receiving nozzle and collection device's drainage nozzle axis coincidence, makes collection device rivers insert standard U type body pipe, accomplishes test water and collects.

According to the invention, the reversing cylinder is positioned at the joint between the test bed body and the upper left of the support plate.

Further, the standard U-shaped volume tube is formed by machining an organic glass tube.

Preferably, the water collecting disc is connected with the water guide barrel through welding, and the water guide barrel is connected with the water tank in a welding mode.

Compared with the prior art, the automatic synchronous detection device for the single-hole flow uniformly distributed in the circumferential direction of the thrust chamber has the following beneficial technical effects:

1. the flow of each hole site is automatically and synchronously measured, and the collecting device is designed, so that the aim of synchronously measuring the flow of all the hole sites of a single product is fulfilled, the test efficiency is greatly improved, and the working strength of test personnel is reduced. The device is used for the repeatability test of the same product, and the comparison is approximately consistent with the comparison of the original manual method; a plurality of product comparison tests are approximately consistent with the comparison of the original manual method; the practical test of a certain thrust chamber proves that after the device is adopted, the number of test operators can be reduced to 1, the test time is shortened by nearly 60%, and the test efficiency is improved by nearly more than 10 times.

2. Different positioning mounting holes are designed according to different products, so that the products are convenient to mount, the process of centering the hole positions and the collecting device is simplified, and the test efficiency is improved.

3. Promote the collecting tray action through the switching-over cylinder, stop the water receiving when the spigot joint dislocation, the water receiving when the spigot joint aligns, the water of collection can flow in standard U type is built up in the volume to effectively reduce manipulation strength, improve test efficiency.

4. The water discharging function of the standard U-shaped volume pipe is realized by installing the direct-acting electromagnetic valve under the standard U-shaped volume pipe, so that the automatic water discharging of the standard U-shaped volume pipe is realized, and the manual mode of manually turning over the test tube disc to discharge water is solved;

5. the size of the cooling liquid jet flow surface is ensured by adjusting the height of the lifting mechanism, and the collecting devices correspond to the circumferential hole positions of the product one by one, so that jet flow of each hole position of the product is completely sprayed in the region of the collecting devices.

Drawings

FIG. 1 is a schematic front view of a single-hole flow automatic synchronous detection device of a thrust chamber according to the present invention;

FIG. 2 is a left side view of FIG. 1;

fig. 3 is a top view of fig. 1.

FIG. 4 is a flow chart of the liquid flow test of the automatic synchronous detection device for single-hole flow of the thrust chamber of the present invention.

The symbols in the figures represent: 1. the device comprises a collecting device, 2, a standard U-shaped accumulation pipe, 3, a lifting mechanism, 4, a laboratory bench body frame, 5, a collecting tray, 6, a water collecting tray, 7, an organic glass waterproof plate, 8, a large fixing plate, 9, a small fixing plate, 10, a water receiving nozzle, 11, a threaded connection type guide pipe, 12, a thrust bearing, 13, a rack, 14, a double-end stud, 15, supporting angle steel, 16, a water discharging nozzle, 17, a water guide bucket, 18, a reversing cylinder, 19, a direct-acting electromagnetic valve, 20, a liquid level photoelectric sensor, 21, a water tank, 22, a hand wheel, 23, a lead screw, 24, a product mounting platform, 25, a tool, 26, a water return port and a water return hose, 27 and a standard U-shaped accumulation pipe support. 28. Test tube return water hose, 29, backup pad.

The present invention will be described in further detail with reference to the following drawings and examples.

Detailed Description

In the research process, the applicant finds that in order to improve the original manual method, a static volume method principle is required to be utilized, a photoelectric liquid level switch is installed at the inlet of a collector, the collection time of jet flow of a cooling hole is recorded by starting and stopping the liquid level switch, the position of the liquid level switch is fixed, so that the volume of the collector corresponding to the sensing moment of the liquid level switch is fixed, and the volume of collected liquid is calibrated and converted into collection quality, so that the flow of the cooling hole can be obtained.

The specific implementation technical scheme and technical principle are as follows:

(1) method for obtaining single-hole flow by volume calibration

When carrying out the product test, will be installed on mounting platform by the test piece earlier, the size of haplopore efflux face is ensured through adjustment elevating system height, make it spray in collection device completely, readjust the flow to rated operating mode again, treat the flow stabilization back, send command signal, make the cylinder drive the collecting tray switching-over, guarantee that the rivers of collection device leakage fluid dram pass through collecting tray and get into standard U type tubular duct, collect every stock efflux respectively through the collector, make every standard U type tubular duct volume reach the settlement volume that can trigger liquid level switch action, record collection time through liquid level switch, thereby obtain the cooling hole flow.

(2) The collecting device is combined with the reversing cylinder to complete the synchronous collection of the jet flow of each hole

A standard U-shaped volume pipe is designed to calibrate a mass value corresponding to the received volume from the beginning of collecting jet flow to the moment when a liquid level switch detects a liquid level. The accuracy of the standard U-shaped volumetric tube collection quality calibration influences the measurement precision of the whole device.

In order to realize the synchronous collection of jet flow of each hole site, all jet flow can be synchronously collected by designing a reversing cylinder according to the distribution characteristics of actual hole sites. According to collection device's structural configuration, distribute from top to bottom adopting, with 12 equal divisions collection device and standard U type volumetric pipe rigidity, and ensure every water discharge nozzle of collection device and the centering of water receiving nozzle above the standard U type volumetric pipe, make the device well rivers can flow in standard U type volumetric pipe completely through water discharge nozzle, in the middle of collection device and standard U type volumetric pipe, can follow the axially rotatory collection dish through the design, and according to device water discharge nozzle distribution position on the collection dish, design rather than the water receiving nozzle of one-to-one, through rotatory collection dish, make device water discharge nozzle, water receiving nozzle and the complete centering of standard U type volumetric pipe, make device water discharge nozzle rivers only can be collected by standard U type volumetric pipe through collection dish water receiving nozzle, just so through the synchronous collection of relapse switching-over realization all efflux.

(3) Automatic control of standard U-shaped integral pipe water receiving and draining by installing direct-acting electromagnetic valve

In order to solve the manual mode that the test-tube rack turned over the water, adopt the direct-acting solenoid valve to control the break-make of standard U type integrated tube bottom, after pressure satisfied condition, make standard U type integrated tube and collection device liquid outlet axis coincidence, the direct-acting solenoid valve is in the closed condition, collection device rivers insert standard U type integrated tube, accomplish experimental water collection after the liquid level triggers liquid level photoelectric sensor, procedure automatic control gas accuse switching-over valve comes rotatory collection tray, standard U type integrated tube stops the water receiving, procedure automatic control solenoid valve opens, standard U type integrated tube water is unified to be discharged to the collection tray through the drainage hose and is directly moved the solenoid valve and close.

(4) Accurate positioning of product jet hole site and collection device

Through designing dedicated receiving arrangement, according to the receipt requirement of the product hole site of being tried, on collection device, according to collection device and the distribution position of each hole site of being tested, design on cantilever beam formula product mounting platform by spacing hole of test piece installation to carry out the sign on spacing hole, make by the test piece according to the sign installation back, each hole site efflux can be totally collected by the device, and the hole site sequence number that the device was collected keeps unanimous with the product, realize product and collection device's accurate positioning, simplify experimental process.

(5) Single-hole flow data automatic synchronous measurement

By developing test special test software, the automatic operation and processing of the single-hole flow deviation are realized. The standard U type volume pipe collection time is measured through the PLC time-recorder, drive the position installation liquid level photoelectric sensor that the catch tray arrived standard U type volume pipe and began the water injection at the cylinder, send high level pulse signal to PLC through the sensor, PLC begins the pulse quantity that the accumulative period is 1ms and begins the timing, when the collecting fluid volume reaches level switch place height, the level switch that corresponds the hole sends high level pulse to PLC, treat that all level switches all send high level pulse after, just obtained the timing pulse number of every test tube, the rethread OPCserver transmits the time to data acquisition software, calculate the pulse number of every test tube through software, can obtain the collection time of every test tube.

A Labview development platform is adopted in the test, upper data acquisition software is developed to complete the acquisition of the rated flow of the test and the processing of test data, various parameters of the test are calculated through the software, the test conclusion is judged, and data files are recorded, so that the automation of the whole flow measurement process is realized.

(6) Product safety protection

The scratch of the injection surface of the product caused by the impact atomization phenomenon caused by the jet flow of the inner ring and the outer ring of the product in the thrust chamber is avoided. The threaded connection type guide pipe is additionally arranged at the center of the collecting device, and the protective sleeve made of fluoroplastic is designed at the guide pipe collecting port, so that the guide pipe can be rotated as required when the guide pipe is adjusted, the hidden danger of scratching products is overcome, and the products are effectively protected.

Therefore, the inventor provides a technical idea for automatically and synchronously detecting the single-hole flow of the thrust chamber, and designs an automatic and synchronously detecting device for the single-hole flow uniformly distributed in the circumferential direction of the thrust chamber. The device passes through switching-over cylinder automatic switch-over test state, realize the automatic water of depositing of standard U type volume pipe through direct solenoid valve, replace artifical stopwatch timing through photoelectric liquid level sensor, guarantee the accurate location of product through special product mounting platform, design circumference haplopore flow synchronous collection measuring device, the cooperation is experimental with observing and controlling system realization all cooling hole haplopore flows receive simultaneously, measure, discharge, improve measurement accuracy and stability, shorten test time, reduce intensity of labour, reach the effect that improves work efficiency and experimental stability.

In addition, by using the design and the use principle of the standard volume tube for reference, the standard U-shaped volume tube is processed and formed by an organic glass tube, and the inner surface of the standard U-shaped volume tube is subjected to precision processing, so that the phenomenon of water wall hanging can be effectively reduced. In order to reduce the residual quantity of the test tubes and reduce the calibration error of the test tubes, the bottom of each test tube is provided with an oblique-mouth bottom groove, two test tubes are connected to form a standard U-shaped accumulated tube, and the water passing part in the oblique-mouth bottom groove is designed into an inclined plane, so that the water in the standard U-shaped accumulated tube can be completely discharged. After the standard U-shaped volumetric tube is manufactured, the following work is performed:

A. calibration of standard U-shaped volume tube

And the standard U-shaped volume tube calibration refers to a mass value corresponding to the received volume when the standard U-shaped volume tube starts to collect jet flow until the liquid level switch detects the liquid level. The accuracy of the standard U-shaped volumetric tube collection quality calibration influences the measurement precision of the whole device and is a key point in the implementation process. The standard U-volume tube was calibrated as follows:

(1) starting the verification, opening the cylinder to enable the standard U-shaped volume pipe to be in a receiving state, and injecting water into the collection grating in a manual simulation jet flow mode;

(2) when the liquid level of the standard U-shaped accumulated pipe rises to the liquid level sensed by the liquid level switch, the liquid level switch immediately sends an instruction, the collection disc is reversed through the air cylinder, and the state that the standard U-shaped accumulated pipe stops collecting in a real test is simulated;

(3) and (3) opening the electromagnetic valve, collecting the aqueous medium in the standard U-shaped volumetric pipe by using a beaker, and measuring the discharged aqueous medium by using an electronic balance to obtain the mass value of the replacement water during the operation between the standard U-shaped volumetric pipe photoelectric switch D1 and the liquid level switch D2.

In order to ensure the calibration accuracy, the average value of the collection quality of the standard U-shaped volume tube is obtained by adopting multiple times of calibration. Considering that water in the standard U-shaped accumulation pipe is easy to hang on the wall and cannot be completely drained, draining the water entering the standard U-shaped accumulation pipe for the first time, and calibrating after the standard U-shaped accumulation pipe is hung on the wall. According to the collection and drainage test of the standard U-shaped integral tube of organic glass, the mass of the wall hanging water of the standard U-shaped integral tube is about 0.3 percent of the whole collection mass, and the flow measurement with the collection time of 50 seconds can be almost ignored.

Meanwhile, in order to fully discharge the water in the standard U-shaped volume pipe and reduce the influence of the residual quantity in the valve and the standard U-shaped volume pipe, after the continuous flow is discharged, the valve is kept in an opening state for 1.5min in a dripping state, and in the period, the valve is actuated to generate vibration, so that after the residual quantity in the standard U-shaped volume pipe is further reduced, the liquid discharge electromagnetic valve is closed. By adopting the measures, the collection deviation caused by the increase of the residual quantity in the standard U-shaped volume tube is reduced, and the verification result is influenced.

After the collecting device is put into use, the test quality can be controlled, and the measurement accuracy is improved.

B. Measurement accuracy analysis

The invention relates to an automatic synchronous detection device for single-hole flow uniformly distributed in the circumferential direction of a thrust chamber, which adopts a static volumetric method to realize flow measurement, a product is installed in the automatic synchronous detection device for single-hole flow uniformly distributed in the circumferential direction of the thrust chamber according to requirements, a liquid supply system is started, liquid flows into a bypass side flow channel of the device at a certain stable flow rate, a starting button of a commutator is started, water flow is changed from the bypass side to a standard U-shaped volume pipe, timing is started, when the position of the liquid in the standard U-shaped volume pipe reaches a specified value, a photoelectric switch is started, a displacer button is closed, the water flow is changed back to the bypass side, and the timing is stopped. The volume and the measuring time of the liquid flowing into the standard U-shaped volume pipe are measured, and the single-hole flow of the cooling hole is obtained.

The formula is expressed as:

in the formula: q. q.s_v-instantaneous volume flow, ml/s;

v-effective volume of standard measuring device (i.e. standard U-shaped volumetric tube), ml;

t is the time measured by the timer, s.

In order to facilitate the use of the device, the effective volume V of a standard measuring device (namely a standard U-shaped volume tube) is subjected to mass calibration through a high-precision electronic balance to obtain the effective mass m. Namely:

in the formula: q. q.s_m-instantaneous flow, g/s;

m-effective volume calibration mass of a standard measuring device (namely a standard U-shaped volume tube), g;

t is the time measured by the timer, s.

The formula (2) expresses a measurement model of the measurement result, and is a basic mathematical model for uncertainty evaluation of the measurement result. The small deviation equation of the formula (1) is linearized to obtain:

the basic expression for the relative standard uncertainty of this measurement is thus:

the expression on the right hand side of equation (3) contains the uncertainty component introduced by the standard gauge (i.e., standard U-shaped volumetric tube) effective volume calibration mass and time measurements.

1) Uncertainty component introduced by mass measurement

(1) Indication of electronic weighing apparatus

The maximum measuring range 6200g of an electronic scale used for calibrating the standard U-shaped volume tube is within the measuring range of 0-500 g, and the tolerance is +/-0.05 g. When the actual calibration is carried out, the using range of the electronic scale is 390 g-410 g, so the allowable error is +/-0.05 g, and the following components are taken into consideration according to rectangular distribution:

(2) resolution of electronic weighing apparatus

The resolution of the electronic scale is +/-0.01 g, and when considered in a rectangular distribution, the method comprises the following steps:

(3) measurement repeatability of single standard U-shaped volume tube

Repeatedly measuring the quality of the collected liquid of the single standard U-shaped volume tube to obtain statistical data, evaluating according to A-type method to obtain standard uncertainty U introduced by the repeated measurement of the single standard U-shaped volume tube₃(m)。

Synthesizing the three components to obtain the standard uncertainty of the quality measurement:

the relative uncertainty is:

2) uncertainty component introduced by time measurement

(1) Photoelectric switch

The initial time for collecting jet flow of the standard U-shaped volume tube is sent by the photoelectric switch, the response time of the photoelectric switch is 1ms, the rectangular distribution is met, and the influence on time measurement is as follows:

(2) liquid level switch

The end time of collecting jet flow by the standard U-shaped volume tube is sent by the liquid level switch, the response time of the liquid level switch is 200 mus, the rectangular distribution is met, and the influence on time measurement is as follows:

(3) programmable controller

The time measurement of flow measurement is realized by a Programmable Logic Controller (PLC), the timing precision of the PLC is 1ms, the rectangular distribution is satisfied, and the influence on the time measurement is as follows:

synthesizing the three components to obtain the standard uncertainty of time measurement:

the relative uncertainty is:

3) resultant uncertainty in flow measurement

From equation 3, the resultant relative standard uncertainty of the flow measurement is:

and measuring the flow measurement expansion uncertainty, and taking a factor k as 2, wherein the expansion uncertainty is as follows:

U(q_m)＝k·u_rel(q_m)＝7.2×10^-3＝0.72％

C. small knot

According to the uncertainty analysis, the main influence factor causing the uncertainty of flow measurement to be larger is the mass measurement component, wherein the influence of collection mass calibration is the largest. In the collection quality calibration process of the standard U-shaped accumulation pipe, the wall hanging amount of the standard U-shaped accumulation pipe, the residual amount in the electromagnetic valve, the trigger consistency of the liquid level switch and other factors can influence the quality calibration, so that the uncertainty of the quality measurement is larger.

The qualified control limit of the product is wide, if the deviation qualified limit of the jet flow single hole is-10.0% to + 10.0%, the uncertainty of flow measurement expansion of the automatic synchronous detection device for the single hole flow uniformly distributed in the circumferential direction of the thrust chamber is 0.7%, and the qualified judgment of the product is not influenced enough.

The inventor adopts the automatic synchronous detection device for the single-hole flow uniformly distributed in the circumferential direction of the thrust chamber, and the device is subjected to a product repeatability test and a plurality of product comparison tests, and error analysis is carried out on the result, so that the influence of the calibration method of the standard U-shaped volume tube on the measurement result of the product is confirmed. Therefore, the following conclusions are made:

(1) and by utilizing small deviation analysis, obtaining main components and influence rules of deviation sources of measurement results, and further carrying out uncertainty evaluation on the automatic synchronous detection device for the single-hole flow uniformly distributed in the circumferential direction of the thrust chamber.

(2) The differences in flow measurement are mainly due to the calibration method of the standard meter. For volumetric measurements, it is crucial to ensure the calibration accuracy of a standard U-shaped volume tube.

(3) The result of the comparison test shows that the manual measurement and the electrical measurement are consistent to the qualification judgment of the product.

D. Advantageous technical effects

By analyzing main influence factors influencing the calibration of the standard U-shaped volume tube, effective improvement means is adopted, effective verification is obtained, and a foundation is laid for the design and the use of the standard volume tube technology in the future.

The main factors affecting the stability of single-orifice flow measurement are identified. The method realizes the measurement uncertainty evaluation of the test measurement result, quantifies the overall test level of the whole liquid flow test system, and stabilizes the quality and reliability of the product liquid test data.

The following are specific examples given by the inventors.

Referring to fig. 1 to 3, the present embodiment provides an automatic synchronous detection device for single-hole flow uniformly distributed in the circumferential direction of a thrust chamber, which is composed of a test bed frame body 4, a lifting mechanism 3 and a product mounting platform 24; wherein:

the lifting mechanism 3 is arranged on one side of the supporting plate 29 above the test bed frame body 4, the product mounting platform 24 is arranged on the lifting mechanism 3, and the height of the product mounting platform 24 is adjusted by rotating the hand wheel 22 to drive the screw rod 23 to rotate; a tool 25 for fixing and sealing a product is arranged on the product mounting platform 24, and a pressure measuring channel is reserved on the tool 25;

the bottom end in the test bed frame body 4 is provided with a water tank 21, a large fixing plate 8 and a small fixing plate 9 are installed in the test bed frame body, the large fixing plate 8 is installed on a supporting angle steel 15, and the supporting angle steel 15 is fixed with the test bed frame body 4 through bolts; the large fixing plate 8 and the small fixing plate 9 are fixedly connected through a stud 14;

a water guide barrel 17 is arranged in the center of the water tank 21, a water collecting tray 6 is arranged above the water guide barrel 17, a collecting tray 5 is arranged above the water collecting tray 6, and a water return port and a water return hose 26 which are connected with the water collecting tray 6 are arranged at the bottom of the collecting tray 5; a water receiving nozzle 10 penetrating through a large fixing plate 8 is arranged at the edge of the collecting tray 5, a standard U-shaped volume pipe 2 is fixed on the large fixing plate 8, and a liquid level photoelectric sensor 20 is connected to the standard U-shaped volume pipe 2; the water receiving nozzle 10 and the standard U-shaped volume tube 2 are fixed on a standard U-shaped volume tube bracket 27 on the small fixing plate 9; a pipeline connected with the water receiving nozzle 10 and the standard U-shaped volume pipe 2 is connected with a test tube water return hose 28 through a direct-acting electromagnetic valve 19, and the test tube water return hose 28 is communicated with a water tank 21;

the middle of the collecting tray 5 is provided with 12 equal parts of collecting devices 1, and the center of the collecting devices 1 is provided with a threaded connection type guide pipe 11; a drain nozzle 16 is arranged at the edge of each equal part of the collecting tray 5; the threaded connection type guide pipe 11 is provided with a thrust bearing 12, and the threaded connection type guide pipe 11 passes through the support plate 29, the collection disc 5 and the water collection disc 6 to be connected with the water tank 21;

a rack 13 is also arranged on the supporting plate 29 above the test bed frame body 4; the organic glass waterproof plates 7 are arranged on four sides of the frame 13;

a reversing cylinder 18 is further arranged in the test bed frame body 4, the reversing cylinder 18 pushes the collecting tray 5 to enable the water receiving nozzle 10 to coincide with the axis of the water discharging nozzle 16 of the collecting device 1, so that water flow of the collecting device 1 is connected into the standard U-shaped integral pipe 2, and test water collection is completed.

In this embodiment, the reversing cylinder 18 is located at the junction between the test bed body and the upper left of the support plate 29. The height of the product can be adjusted by the mounting platform 24, and the height can be adjusted according to the jet angle of different products, so that jet water can be collected in the collecting tray 5.

The collecting device 1 collects the jet flow of the product grade in a directional way through the water discharging nozzles 16 distributed on equal parts of the holes 12 along the circumferential direction.

The direct-acting electromagnetic valve 19 arranged below the standard U-shaped volume pipe 2 can realize the automatic control of the water receiving and discharging of the standard U-shaped volume pipe 2.

The standard U-shaped volume tube 2 is fixed on a standard U-shaped volume tube bracket 27, the standard U-shaped volume tube bracket 27 is connected with the small fixing plate 9 through bolts, a water receiving nozzle 10 and a photoelectric liquid level sensor 30 are respectively arranged at the inlet of the standard U-shaped volume tube 2, and a direct-acting electromagnetic valve 19 is arranged at the bottom of the standard U-shaped volume tube 2;

the collecting tray 5 is arranged on a thrust bearing 12 and is pushed by a reversing cylinder 18 to change the position, and 12 water nozzles 10 are uniformly distributed on the collecting tray 5 in the circumferential direction;

the collecting tray 5 is arranged below the supporting plate 29, the middle of the collecting tray 5 is provided with 12 equal parts of the collecting device 1, and the middle of the collecting device 1 is provided with a threaded connection type guide pipe 11 through threaded connection.

The reversing cylinder 18 controls the action of the cylinder through a solenoid valve to control the action of the collecting tray 5.

The standard U-shaped volume tube 2 is formed by processing an organic glass tube, and the inner surface of the standard U-shaped volume tube is subjected to precision processing. The standard U-shaped volume tube 2 is fixed on the standard U-shaped volume tube bracket 27;

the collecting tray 5 is provided with a water return nozzle and a water return hose 26, water flows into the water collecting tray 6 through a water discharge pipeline when water is not collected, the water collecting tray 6 is connected with the water guide barrel 17 through welding, and the water guide barrel 17 is connected with the water tank 21 through welding;

a test tube water return hose 28 is installed below the direct-acting solenoid valve 19, and is used for discharging water collected in a test tube (a standard U-shaped integral tube 2) and returning the water to the water return tank 21 through the hose.

The direct-acting electromagnetic valve 19 can be controlled to be opened/closed by a measurement and control system, and further controls whether the test tube (a standard U-shaped integral tube 2) drains water or not.

Fig. 4 shows a flow test process of the automatic synchronous detection device for single-hole flow uniformly distributed in the circumferential direction of the thrust chamber in the embodiment.

And (3) starting a liquid flow test, mounting a product on the mounting platform 24, starting the liquid flow test, enabling liquid to flow into a bypass side flow channel of the device at a certain stable flow rate, sending an instruction according to software, starting the reversing cylinder 18 to enable the water flow to be changed from the bypass side to the standard U-shaped integral tube 2, triggering the liquid level photoelectric sensor 20 to start timing and receiving when the position of the liquid in the standard U-shaped integral tube 2 reaches a specified value, obtaining the collection finishing time, closing the reversing cylinder 18, enabling the water flow to be changed back to the bypass side, and stopping timing. The liquid volume flowing into the standard U-shaped volume pipe 2 and the measuring time are measured, and therefore the single-hole flow is obtained.

The specific operation is as follows:

before the test, the product is placed on the product mounting platform 24 according to the requirement of the positioning hole, a tool for the product test is mounted on the product mounting platform 24, a sealing ring is arranged inside the tool to fix and seal the product, and a pressure guiding opening is reserved on the tool and connected with a pressure transmitter to measure the pressure of the inlet of the product. In the test process, the height of the lifting mechanism 3 is adjusted to ensure the size of the cooling liquid jet surface to be completely sprayed in the area of the collecting device 1, the collecting device 1 and the circumferential hole positions of the product are uniformly distributed into 12 equal parts one by one, and water is collected and flows into the drainage nozzle 16 through drainage; when the inlet pressure does not reach a set value, the reversing cylinder 18 pushes the collection disc 5 and the water discharging nozzle 16 to be staggered, water in the water discharging nozzle 16 flows into the collection disc 5 and flows into the water collecting disc 6 through the return port and the return water hose 26; after the rated working condition is reached, the upper computer sends an instruction to enable the reversing cylinder 18 to push the collecting tray 5, the water discharging nozzle 16 is vertically aligned with the water receiving nozzle 10 on the collecting tray 5, the axis of the standard U-shaped volume pipe 2 is overlapped with the axis of the liquid outlet of the collecting device 1, and the water flow of the collecting device 1 flows into the standard U-shaped volume pipe 2; when the liquid level rises to the trigger liquid level of the liquid level photoelectric sensor 20, the collection work is finished; and then the collecting tray 5 is pushed by the reversing cylinder 18, so that the standard U-shaped volume pipe 2 is separated from the liquid outlet of the collecting device 1, the standard U-shaped volume pipe 2 stops receiving water, and the collecting work is finished. The collection end time is obtained through the signal triggering time of the liquid level photoelectric sensor 20, the collection time of the standard U-shaped volume pipe 2 is further obtained, meanwhile, the volume of the standard U-shaped volume pipe 2 is calibrated and converted into mass when the liquid level photoelectric sensor 20 triggers, and the measurement and control system obtains the flow rate of the cooling liquid through calculation. After the collection is finished, the direct-acting electromagnetic valve 19 arranged below the standard U-shaped volume pipe 2 is opened, the water in the standard U-shaped volume pipe 2 is discharged into the water tank 21 through the test tube water return hose 28, and after the water is discharged, the direct-acting electromagnetic valve 19 is closed, and the test of a single product is finished.

Note that: when the test pressure does not meet the condition, the collecting device 1 collects water and flows into the collecting tray 5, and the collected water is discharged into the water collecting tray 6 through a water return port at the bottom of the collecting tray 5 and a water return hose 26. During detection, collecting starting time is given through the reversing cylinder 18, collecting ending time is obtained through the liquid level photoelectric sensor 20, meanwhile, the volume of the standard U-shaped volume pipe 2 is calibrated and converted into collecting quality, and the flow of the cooling hole is obtained.