The screw drilling tool test bench is a large-scale test device for testing the performance index of the whole screw drilling tool. This device tests various performance parameters of screw drilling tools, including: drilling tool output torque, output speed, output power, input power, circulating flow, inlet liquid pressure, outlet liquid pressure, inlet medium temperature, total efficiency, etc. This test bench can meet all the performance tests of Φ120-Φ244 screw drilling tools, and provide accurate parameter indicators for judging the manufacturing, maintenance and field application of screw drilling tools.
2. Basic parameters:
Loading torque range (including "test torque"): 0-20000 N · m
Speed measurement range: 0 ~ 800 rpm
Inlet pressure measurement range: 0 ~ 8 MPa
Outlet pressure measurement range: 0 ~ 1 MPa
Cyclic flow measurement test range: 0 ~ (35-40) l / s
Inlet medium temperature: 0—100 ℃
Test screw drill specifications (outer diameter): φ120 ~ φ244 mm
Mainframe appearance (length × width × height): 14 × 1.2 × 1.6 (m)
Test medium: clean water
three. Test principle
According to the actual working conditions of the screw drilling tool, the circulating fluid (drilling fluid) is sent to the screw drilling tool by the surface reciprocating mud pump through the drill string, and its displacement is relatively stable; and the output load of the screw drilling tool mainly includes the bottom The counter torque generated when the drill bit breaks the rock, and the friction torque caused by the weight on the drill bit acting on the support bearing of the screw drill. According to this working characteristic, the basic principle of screw drill performance test can be proposed:
The liquid is input to the inlet end of the screw drilling tool through the circulation system. On the premise that the circulating liquid flow rate of the screw drilling tool is maintained at a given value, the drilling tool is made to apply different torque loads to the power output end of the screw drilling tool. Work stably under different braking torques. Test the output torque T, output speed n, circulating flow Q, drill inlet pressure P1, drill outlet pressure P2 and other parameters under different working conditions. After data processing and calculation, the characteristic parameter table and characteristic curve of the power drill are obtained.
For screw drills, the pressure drop is taken as the abscissa, and the characteristic curve includes,
T- △ P, n- △ P, Wout- △ P, and η- △ P characteristic curves. \
4. Main components and functions of the test bench
The screw drill tool performance test rig is mainly composed of three parts: the main body of the test frame, the test system and the circulation system, as shown in Figure 1.
4.1 Experiment host
The host of the test bench is the general term for all the mechanical devices that make up the test bench. Including: water distribution transmission assembly, drilling tool fixing mechanism, drilling tool push-pull mechanism, base, experimental tooling and hydraulic station and other components.
4.2 Test system
This system is the core of the power drill performance test bench. The system consists of a loading system, various sensors and corresponding secondary instruments, a computer, A / D, D / A, RS485 interface, and measurement and control software. It realizes the collection of experimental data, the control of the experimental process, the processing of performance parameters, and performance prediction.
Main contents and functions of measurement and control software
The measurement and control software is developed using the Chinese character platform under the Windows environment. The main contents and functions of the measurement and control software are:
①. Performance test The parameters of the test drilling tool: output torque, speed, circulating flow, leakage flow, inlet pressure, outlet pressure, inlet medium temperature; calculation parameters: inlet and outlet pressure difference, input power, output power, total efficiency, etc. In order to meet the requirements of operators at different levels, the measurement and control system is designed with three automatic operation schemes: "automatic", "semi-automatic" and "manual" to meet the requirements of different operators.
②. Data processing Calculate and process the data measured in the test to obtain the performance parameter table of the drilling tool, and draw the characteristic curve of the power drilling tool, a total of four curves. For screw drilling tools, including torque-pressure drop, speed-pressure drop, output power-pressure drop, and total efficiency-pressure drop curve; for turbo drilling tools, including torque-speed, pressure drop-speed, output power-speed, total Efficiency-speed. As shown in Figures 4 and 5
③. Performance prediction According to the user's needs, according to some test data of a drilling tool at a displacement, predict the complete performance parameters of the drilling tool at different displacements and output a performance parameter table to draw a characteristic curve.
④. Signal self-test Perform self-test on each test signal to check the correctness of the collected data
4.3 Circulatory System
This system is mainly used to provide a certain pressure and flow of power fluid (working medium is clean water) for the performance test of screw drilling tools. The head (or outlet pressure) and displacement of the pump set are related to the pressure drop and circulating flow of the tested drilling tool, and are also limited by the user's power distribution capacity. For commonly used Φ120-Φ244 screw drilling tools, the rated total head is not less than 650 meters (or 6.5MPa), and the rated displacement is not less than 35 liters / second.