Method for calculating steam admission enthalpy of air-cooling condenser of direct air-cooling unit

Abstract

The invention discloses a method for calculating steam admission enthalpy of an air-cooling condenser of a direct air-cooling unit. The method specifically includes the first step of measuring the flow of condensed water entering a deaerator, the steam leakage flow of a front shaft seal and a rear shaft seal of a high pressure cylinder and the steam leakage flow of a front shaft seal and a rear shaft seal of an intermediate pressure cylinder, the steam admission flow of a low pressure shaft seal, the steam leakage flow of a steam admission valve rod of the high pressure cylinder and the steam leakage flow of a steam admission valve rod of the intermediate pressure cylinder, and the flow of seal water entering a feed pump; the second step of calculating the steam extraction flow, the water feed flow, the main steam flow, the high pressure cylinder exhaust steam flow and the reheat steam flow from the first section to the fourth section according to energy balance and mass balance of a high pressure heater and the deaerator; the third step of calculating the steam extraction flow from the fifth section to the seventh section according to heat balance and mass balance of a low pressure heater, and calculating exhaust steam energy and exhaust steam flow of the lower pressure cylinder of a turbine according to energy balance and mass balance of the turbine; the fourth step of calculating exhaust steam enthalpy of the low pressure cylinder, namely, the steam admission enthalpy of the air-cooling condenser, and enabling the steam admission enthalpy to serve as a benchmark for calculating heat load of the air-cooling condenser. The measuring results can be more accurate.

Description

technical field [0001] The invention relates to a method for calculating the inlet steam enthalpy of an air-cooled condenser of a direct air-cooling unit. Background technique [0002] At present, in my country's "Three North" regions, air-cooled units are developing rapidly. Since the air-cooled condensers of the air-cooled units put into production in the early stage mostly adopt foreign technology and products, the acceptance test of domestic air-cooled condensers is basically in accordance with foreign VGB-R131Me The guideline proceeds. The domestic test standards and specifications for air-cooled condensers are mainly the industry standard DL / T552-1995 "Test methods for air-cooled towers and air-cooled condensers in thermal power plants", which includes specific requirements for tests on air-cooled towers and air-cooled condensers . [0003] Both of the above two test standards use the state point of the low-pressure cylinder to reheat and extract steam to draw the exp...

AI Technical Summary

Problems solved by technology

The above two factors will lead to the difference between the actual steam expansion process and the design expansion process, which will cause the steam expansion process line in the low-pressure cylinder to present a nonlinear relationship, resulting in the determined low-pressure cylinder exhaust steam enthalpy, that is, the condenser inlet steam enthalpy. Large deviations will eventually affect the accuracy of the performance calculation results of the condenser

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