Application Research on Testing Efficiency of Main Drainage Pump in Coal Mine Using Thermodynamic Theories

Abstract

The efficiency of a drainage pump should be tested at regular intervals to master the status of the drainage pump in real time and thus achieve the goal of saving energy. The ultrasonic flowmeter method is traditionally used to measure the flow of the pump. But there are some defects in this kind of method of underground coal mine. This paper first introduces the principle of testing the main drainage pump efficiency in coal mine using thermodynamic theories, then analyzes the energy transformation during the process of draining water, and finally derives the calculation formulae of the pump efficiency, which meet the on-site precision of engineering. On the basis of analyzing the theories, the protective sleeve and the base of the temperature sensor are designed to measure the water temperature at inlet and outlet of the pump. The efficiencies of pumps with two specifications are measured, respectively, by using the thermodynamic method and ultrasonic flowmeter method. By contrast, the results show that thermodynamic method can satisfy the precision of the testing requirements accuracy for high-flow and high-lift drainage pump under normal temperatures. Moreover, some measures are summed up to improve the accuracy of testing the pump efficiency, which are of guiding significance for on-site testing of the main drainage pump efficiency in coal mine.

Application of CFD to the Design of Manifolds Employed in the Thermodynamic Method to Obtain Efficiency in a Hydraulic Turbine

“…where e a 21 is approximated relative error, calculated by Equation (5). φ are the values of critical variables.…”

“…In addition, the temperature of the extracted water should be continuously monitored by thermometers of at least ± 0.05 K precision and 0.01 K sensitivity [2]. According to different authors, Pt-100 Resistive Temperature Detectors (RTD's) are commonly used for measurement due to their high stability and precision [3][4][5].…”

Design of coal mine drainage system

“…Excess water discharge is flowed to the surface using a drainage system. The pumping system [24] is one of the most important parts of mine water handling in coal mining research areas. Settling pond [25] is designed with certain dimensions to be able to precipitate sediment.…”

Numerical study of upstream disturbances on the performance of electromagnetic and ultrasonic flowmeters

“…At the present time, technologically advanced electromagnetic (EM) and ultrasonic (US) flowmeters are used to accurately meter liquid flows. They present certain advantages (Zhang et al, 2014;Zheng et al, 2015), which can be exploited in diverse areas (Baker, 2011;Shi et al, 2015), including rural irrigation and water systems (Shang, 2017;Massey et al, 2017;Massuel et al, 2017).…”