Energy-saving assessment method for low-pressure economizers used in thermal systems of power plants

Abstract

The invention discloses a low-pressure economizer energy saving assessment method applied to a power plant heat system. The method includes the steps that step1, the heat balance diagram parameters, generated before a low-pressure economizer is installed, of the power plant heat system are obtained; step2, the heat balance diagram parameters, generated after the low-pressure economizer is installed in a parallel connection or series connection mode, of the power plant heat system are obtained, and in combination with the step1, the change of extraction flow of each stage of is obtained; step3, according to the change, obtained in the step2, of the extraction flow of a heater of each stage, based on the extraction flow conservation principle, the variation of the power capability of a turbine is calculated; step4, the variation of the coal consumption of a power plant is calculated and used for assessing the energy saving quantity of the low-pressure economizer, wherein the larger the variation of the coal consumption of the power plant is, the larger the energy saving quantity of the low-pressure economizer will be. According to the method, the low-pressure economizer can be reasonably installed; the load change of the heater of each stage can be displayed, the influence on the coal consumption of the system from the power of an auxiliary engine can be displayed as well, and therefore calculation results are more real and more reliable.

Description

technical field [0001] The invention relates to the field of energy saving of low-pressure economizers, in particular to an energy-saving evaluation method of low-pressure economizers used in thermal systems of power plants. Background technique [0002] As the country pays more and more attention to energy saving and emission reduction, power plants pay more and more attention to improving boiler efficiency and reducing coal consumption in power generation, and a series of important energy saving measures have been put forward. Thermal power plants consume 50% of my country's total coal output, and its exhaust heat loss is the largest among all heat losses of power plant boilers, generally 5% to 8%, accounting for 80% or more of the total heat loss of boilers. The main factor affecting the heat loss of the exhaust gas is the temperature of the exhaust gas of the boiler. In general, when the temperature of the exhaust gas increases by 20°C, the heat loss of the exhaust gas i...

AI Technical Summary

Problems solved by technology

In the calculation process of the equivalent enthalpy drop method, it only needs to be calculated according to the parameters of the recuperation system, and it cannot directly display the load change of each stage heater, nor can it display the influence of the change of auxiliary power on the coal consumption of the system

Images