A Method for Calculating the Thermal Efficiency of Pipelines in Large Thermal Power Plants

Abstract

The invention discloses a method of calculating pipeline heat efficiency of a large thermal power plant. Pipelines of the power plant comprise a main steam pipeline, a cold reheating pipeline and a heat reheating pipeline, and are characterized in that heat losses in each pipeline include a flow loss Q<1> and a heat dissipation loss Q<2>, the flow loss Q<1> = (S - S<a1>) x T<a1> x D<0>, the heat dissipation loss Q<2> = (S<a2> - S<a1>) x T<a2> x D<0>, the flow loss Q<11> and the heat dissipation loss Q<21> of the main steam pipeline, the flow loss Q<12> and heat dissipation loss Q<22> of the cold reheating pipeline and the flow loss Q<13> and heat dissipation loss Q<23> of heat reheating pipeline are respectively calculated, the pipeline heat efficiency eta = 1 - (Q<11> + Q<12> + Q<13> + Q<21> + Q<22> + Q<23>) / Q, the Q therein is a heat load of a boiler outlet, and assessing heat economy of a steam-turbine generator set and correctly analyzing heat economy of the whole power plant are facilitated.

Description

technical field [0001] The invention belongs to the field of thermal efficiency calculation of a thermal system of a large-scale thermal power plant, and specifically relates to a method for calculating the thermal efficiency of a pipeline of a large-scale thermal power plant. Background technique [0002] During the implementation of domestic or international large-scale thermal power plant projects, thermal economics will be evaluated. In the total thermal efficiency of large-scale thermal power plants, the thermal efficiency of pipes is one of its important components and has great potential. In the current conventional calculation method, the pipeline efficiency takes into account heat loss, auxiliary system loss and leakage loss of working fluid with heat. When calculating the heat dissipation loss of the pipeline, the heat dissipation loss of the pipeline is calculated by using the enthalpy method, which does not effectively express the useful work loss of the steam. ...

AI Technical Summary

Problems solved by technology

However, the calculation of pipeline efficiency through enthalpy change is inaccurate and may be overestimated, resulting in a disadvantageous position for EPC contractors when making performance guarantees, increasing the risk of being assessed and the cost of fines, both domestically and internationally. The thermal economy of the power plant is closely related to the thermal efficiency of the pipeline

However, people tend to unilaterally think that the thermal efficiency of pipelines only reflects the insulation and leakage of pipelines, and ignores the loss of working capacity caused by the heat loss of working fluid flow, thus underestimating the impact of pipeline heat loss

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