Investigation On The Design And Optimization Of Main Steam Pipeline For Coal Gasification Heat Recovery Power Station

Utilizing the waste heat to generate electricity from power stationin steel industrycoal gasificationis one of the key targetsfor the long-term energy saving special planninginthe China. However, due to the charactericticof the gas fuel, the advanceddesign and optimization of the main steam pipeline should be carried outto adapt these special conditions and meet the requirements of the goverment.Therefore, in this paper, the aim of this study is to design and develop a optimal programme on main steam pipelinefor a new-built coal-gas based power station.According to the gas yielding ability and the utilization in this steel industry compan y, refer to the relevant standards as well. The design pressure of main steam pipeline is 9.81 MPa, the temperature is 545? and the material code is 12Cr1 MoV.Considering the recommendatory flow velocity of the main steam pipe and the pipe specification of the super-heater outlet, the main steam pipe is set to ?194×18 mm. Meanwhile, the insulation layer thickness is 200 mm when aluminum silicate cotton is served as insulation material. The largest design space of pipe supporting frames should be no more than 5.7 m when the strength, stiffness and rules of old pipe are taken into account. and analyzed the type of pipeline supporting frames, four kinds of preliminary design schemes of the main steam pipeline are put forward in view of the concise and fluent of pipeline, the installation positions and numbers of pipeline supporting frames.Using AUTOPSA software, the maximum primary stress value is calculated under the SUS primary stress check condition. andthe maximum secondary stress value is calculated under the EXP secondary stress check condition. the value of thrust and torque to the pipeline are calculated under the OPE operating condition. Spring hangers node thermal displacement is calculated through the EXP thermal expansion condition. And the factors affecting pipeline safety are analyzed. Meanwhile the affecting factors of the economy of the pipeline are also analyzed, including pressure drop, main steam pipeline of investment and operation cost.To evaluate these 4 programs by considering the investment cost, pressure drop, main tenance fees, stress, force and moment that are interact between load and pipelines.operat ion and maintenance cost, stress,and the force and moment to the pipeline. the paper Uses the analytic hierarchy process to determine the evaluation index, establish the hierarchical model and construct two judgment matrix, also conducts the single-level sort and total sort of consistency test. we can obtain the weight of index system of main steam pipeline eventually,. Finally, the paper constructs the fuzzy relation matrix. And using the fuzzy comprehensive evaluation method to make a comprehensive evaluation for the preliminary design schemes. We can obtain the membership degree of the scheme one is the highest, which the weight value is 0.8518. Followed by the scheme four, which the weight value of 0.7225.and the scheme three is the worst, which the weight value is 0.6515. Although the piping layout of scheme one is concise and fluent, and has the less number of Pipe element, and the highest membership degree, due to there is lack of root position of support and hanger actually. So in the actual engineering, we should not only consider the piping layout that is concise and fluent. But also combine with the actual situation to ensure that the operation of pipeline and the system is safe and reliable.To sum up, the scheme four is chosen as the final construction scheme, The paper makes a s specific layout of main steam pipeline.