Accurate measurement method of pump efficiency in efficiency measurement of pump thermodynamic performance test

Abstract

The invention relates to an accurate pump efficiency measuring method used in pump thermal performance test efficiency measurement. At present, pump efficiency result accuracy greatly depends on the pressure and temperature accuracy of a pump inlet / outlet in pump thermal performance test efficiency measurement. The method includes the following steps that only a thermocouple A, a pressure gage A, a thermocouple B and a pressure gage B verified to be qualified are used for measurement; the thermocouple A and the pressure gage A are installed at the water inlet of a pump at first, and the thermocouple B and the pressure gage B are installed at the water outlet of the pump for measurement; then the thermocouple B and the pressure gage B are arranged at the water inlet of the same pump, and the thermocouple A and the pressure gage A are arranged at the water outlet of the same pump for measurement; and the pressure average value P1 serves as inlet pressure of the pump efficiency test at this time, the pressure average value P2 serves as outlet water pressure of the pump efficiency test at this time, and the values are substituted into a formula to calculate pump efficiency. The method is easy to operate, and capable of ensuring that the measured pump efficiency is more accurate.

Description

technical field [0001] The invention relates to a method for accurately measuring pump efficiency, in particular to a method for accurately measuring pump efficiency in the efficiency measurement of pump thermodynamic performance tests. Background technique [0002] In the prior art, in the measurement of the efficiency of the pump thermal performance test, the method of measuring the temperature and pressure of the inlet and outlet water of the pump usually uses two thermocouples (pressure gauges) to separately measure the temperature (pressure) of the inlet and outlet water of the pump, and finally take the temperature of each thermocouple during the test. (Pressure gauge) The average value of the measured value, because the inlet and outlet water temperature (pressure) of the pump has a greater influence on the pump efficiency test results, the accuracy of the pump efficiency results in the efficiency measurement of the pump thermal performance test has a greater impact on...

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Problems solved by technology

[0002] In the prior art, in the measurement of the efficiency of the pump thermal performance test, the method of measuring the temperature and pressure of the inlet and outlet water of the pump usually uses two thermocouples (pressure gauges) to separately measure the temperature (pressure) of the inlet and outlet water of the pump, and finally take the temperature of each thermocouple during the test. (Pressure gauge) The average value of the measured value, because the inlet and outlet water temperature (pressure) of the pump has a greater influence on the pump efficiency test results, the accuracy of the pump efficiency results in the efficiency measurement of the pump thermal performance test has a greater impact on the accuracy of the pump inlet and outlet pressure temperature. The dependence of the efficiency of the feedwater pump is relatively high. Under the condition that other test links are accurate, other test conditions are satisfied, and other auxiliary flow measurements are accurate, the efficiency measurement results of the feedwater pump are highly dependent on the accuracy of the measurement accuracy of the inlet and outlet temperature of the feedwater pump. The measurement accuracy of the inlet and outlet pressure of the circulating water pump has a great influence on the measurement results of the efficiency of the circulating water pump

"Journal of North China Electric Power University" published in October 2000, Volume 27, Issue 4, Pages 88-92, in the research progress of measuring pump efficiency by thermodynamic methods, although a relatively good formula for calculating pump efficiency is recorded, but this The calculation formula is still greatly affected by the temperature (pressure) of the inlet and outlet water of the pump. If the existing measurement method is used to measure the temperature (pressure) of the inlet and outlet water of the pump, the measurement accuracy of the thermocouple is very high, which not only greatly increases the equipment cost. Investment costs, and greatly increase the cost of thermocouple maintenance, will also lead to large deviations in pump efficiency measurement, and it is difficult to rule out test random errors and instrument errors

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