Flow measuring method for thermal power generation unit independent low pressure heater drain pump based on energy balance

Abstract

A flow measuring method for a thermal power generation unit independent low pressure drain pump based on energy balance. The thermal power system in the invention is composed of an independent low pressure heater (low pressure heater for short) and a drain pump; wherein, the drain pump is adopted to mix the low pressure heated drain water with condensation water at the outlet of the drain pump, and no other drain water flows in for low pressure heat release. Low pressure heated steam extraction temperature and pressure, outlet water temperature, pressure and drain water temperature can be obtained from the databases of a thermal power plant supervisor information system (SIS) or a distributed control system (DCS); the steam extraction enthalpy of the heater, the low pressure heater outlet water enthalpy and low pressure heater drain water enthalpy are obtained through calculation. A heat transfer balance equation is created for the low pressure heater, a flow balance equation and a mixing point thermal balance equation are created for the drain pump outlet water of the low pressure heater and the low pressure heater outlet water mixing point; a soft measurement module is deduced through the balance equations, and the flow portion of the drain water is obtained through calculation. Finally, combined with the condensation water detection value in the SIS or DCS database, the drain pump flow is figured out accordingly.

Description

Technical field [0001] The invention relates to an energy balance-based method for measuring and calculating the flow of an independent low-heat drain pump in a thermal power unit regenerative system, which belongs to the field of soft measurement. Background technique [0002] With the expansion of the capacity of thermal power units, the impact of the regenerative system on the units has attracted more and more attention. In the regenerative heater, in order to improve the regenerative effect of the surface heater, the low-pressure heater usually has a drain pump. The measurement of the drain pump flow rate has an important influence on the performance monitoring of the drain pump, the optimized operation of the drain pump, the analysis of the operation status of the heater group, and even the heat balance calculation of the regenerative system. Therefore, it is necessary to conduct online monitoring of the drainage pump flow. There is no report on the measurement and calcula...

AI Technical Summary

Problems solved by technology

After adding this measuring point, there will be a certain impact on the flow rate, and it will take manpower and material resources to maintain it

Therefore, it is time-consuming and labor-intensive to directly solve the problem of the drainage pump flow from the hardware aspect, and there are many inconveniences

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