Performance Test System Of Hydrautic Drived Turbine For Hose Reel Irrigators

The water turbine is a power machinery which converts the kinetic energy into mechanical energy, but in addition to the requirement of efficiency of water turbine, it also requires a wide range of speed adjustment. As a core component of winding irrigation machine, water turbine performance characteristics determine the size of the output power and hydraulic torque of drive device, also it has a significant impact on the performance of winding irrigation sprinkler irrigation machinery, thus it is necessary to analysis the performance characteristics of the turbine. Because of the complexity of the turbine internal flow condition, there is no complete theoretical model that can accurately describe the dynamic characteristics of the water turbine, thus, only by the way of trial, figuring out the water turbine flow under different operating points, such as import and export pressure, power, efficiency, torque and speed and other performance data, and with the basis of a large number of experimental data, to deal with performance parameters of water turbine and use the most appropriate method of curve fitting to curve fitting, error analysis, accuracy calculations and results output. However, the existing water turbine performance test systems cannot achieve the synchronous acquisition of water turbine performance parameters, determination of abnormal data point, online curve fitting and error analysis, real-time display and output reports. Research and conclusions for the existing problems were the followings:(1) We establish the water turbine performance test systems based on Lab VIEW virtual instrument technology. Through the analysis of water turbine test requirements, building water turbine performance testing hardware system around the water turbine test platform, and design signal conversion circuit and the processing circuit and the corresponding power supply circuit to solve the problem of inconsistent input characteristic between sensor output signal and Lab VIEW data acquisition card. The water turbine performance test system can simultaneously measure the instantaneous values of the performance parameters and process simultaneously, and avoid the problem of value of parameter, to reduce the impact on the performance curve and improve the measurement accuracy of the data.(2) Due to the presence of outside interference and experimental environmental restrictions and other conditions, the collected data may deviate from the true value. Therefore, applying polynomial fitting to identify and amend outliers points of torque, speed, flow, power and efficiency of water turbines presented in the data, and design the corresponding Lab VIEW program. This method can effectively avoid the problems of up-forward or down-forward of performance curve because of abnormal data points, and reduce the impact of the external environment on the water turbine performance curve.(3) Aiming at the problems of difference fitting and Least squares polynomial, to improve the method of Least squares polynomial algorithm, and to design the least-squares polynomial algorithm based on orthogonal polynomial and to conduct the error analysis of curve fitting. And we verify the feasibility of fitting algorithm based on orthogonal polynomials of least squares by experiments, and the error results obtained by the proposed algorithm can meet the system requirements for the accuracy of the curve as well as getting good effect of complex curve fitting.(4) Using of ActiveX technology provided by LabVIEW, to design program of test report generator, to output the performance parameters of water turbines, curve fitting and test results into an Excel spreadsheet; In the LabVIEW front panel window designing system operating panel and display interface, displaying real-time instantaneous values of the parameters and real-time fitting curve on system operating interface, to create a better human-computer interaction environment. Finally, creating a project file of water turbine performance test systems, generating applications and the software installation package, making it easy to expand functionality of the program and other test systems.