Design optimization analysis of steel single-frame main plant in thermal power plant

Abstract

Steel single frame has many advantages, such as high strength, light weight and high stiffness, and so on, so it has been more widely used in thermal power plant buildings. In order to improve the quality of steel single frame, it is necessary to optimize the design of thermal power plant plant according to the specific production situation of thermal power plant, taking into account the influencing factors in all aspects. In this paper, taking the specific project as an example, the steel single-frame main plant of thermal power plant is analyzed and introduced, and specific design optimization measures are put forward, so as to ensure the design quality.

 

The plant is the most important part in thermal power plant, which can ensure the production work in an orderly and smooth way. The steel single-frame plant of thermal power plant needs to reserve some holes in advance according to the requirements of the process, so that its load-bearing capacity and stiffness will be affected. Therefore, it is necessary to focus on the design optimization of the steel single-frame plant in the construction of the plant, so as to ensure the structural performance of the plant, so that the value of the plant can be maximized.

 

1 Engineering basic information

 

The plant of a thermal power plant consists of two parts: steam engine room and coal bunker room, because of its own process demand, there is no need to set the deoxidizing room inside. The longitudinal length of the plant is 81m, the horizontal length is 45m, the spacing of the longitudinal columns is 12m and 9m respectively, and the transverse length of the steam engine room is 30m. the outer walls of the plant are closed with pressurized steel plates, and the infill walls are set up in the demarcation of the steam engine room, the coal silo room, and other localized positions respectively. The running floor, double-slope roof and intermediate floor make up the steam engine room, and their dimensions are 12 m, 29.8 m and 6.0 m. The turbine generator is laid out in the central position of the steam engine room in the island type, and the high and low heaters can be arranged in the vertical type. In addition, two pulverized coal hoppers and four steel coal hoppers need to be laid in the belt layer and coal hopper layer, and four coarse powder separators and two fine powder separators need to be laid in the position of the roof. The steel structure of the plant is connected with each other through the boiler steel frame and the platform in front of the furnace, and the platform in front of the furnace is supported by the sliding support on the boiler steel frame, and the boiler steel frame and the structure of the plant do not affect each other, and at the same time, combined with the specific actual situation, the parameters are adjusted appropriately within a reasonable range, and generally, the site is designed as Class II, and the roughness of the ground is designed as Class B, and the basic seismic intensity is designed as 7 degrees, and the defense is needed to According to the 8 degree seismic requirements to ensure that the wind pressure is 0.67KPA.

 

2 Optimize the design of plant structure

 

Generally speaking, the structural plane of the plant is regular, and the floor slab may be discontinuous because of the large opening design, and the chance of torsion will increase once an earthquake occurs. In addition, the distribution of floor live load is not very uniform and is very large, especially concentrated distribution of coal hoppers, powder hoppers, high and low pressure heaters and other equipment, and some of the higher floors on the deployment of some of the equipment. The seismic performance of the plant will be affected to a large extent. To plant the design of quality assurance, in addition to careful analysis and study of the parameters, but also need to reasonably adjust the structure of the layout, so that in the basic engineering budget is met on the basis of the structural system design is more reasonable, economic, and performance will become more excellent.

 

2.1 Analyze the plant structure

 

The two-story steam engine platform steel beams, the frame and support between the coal bunkers and the columns of the steam engine room a column constitute the transverse structure of the plant, and the frame between the coal bunkers is connected to the upper and lower parts by the large-span solid web steel beams on the roof.

 

The steel beams of the steam engine platform and the a-columns of the steam engine room are connected. In this project there is no need to set the deoxidizing room in which only the single column frame between the coal bunker is located in the transverse position, which does not have a strong bearing capacity when subjected to horizontal seismic forces and wind loads, and should be used in the way of stiffening plus bracing to design the unidirectional frame, and cross cross bracing needs to be designed on the axial belt layer and penetration of the axial belt layer which need to bear the load of some equipment. If the process conditions permit, some vertical supports can be set in the two-story platform of the steam engine room, and two vertical continuous vertical supports are designed and arranged in the relevant positions of the frame. The compressed steel plate can be used as the permanent low mold of the steam engine room, the floors of each level and the roof between the coal silos, and 100m thick reinforced concrete will be poured on the mold. The pressurized steel plates were penetrated and welded with cylindrical head weld nails on the upper flanges of the steel beams.

 

2.2 Optimize the design of plant structure

 

Optimization of plant structure is mainly to optimize the support cross-section and vertical support between columns, according to which the structure of the plant can be improved, but also to ensure that the overall structure of the plant is more rational and scientific.

 

2.2.1 Optimization of vertical support between columns

 

In the process of designing the steel structure of the plant, it is necessary to make the whole force structure more reasonable and improve the lateral resistance, so the designers will use a lot of support frames, but when setting the vertical support between columns, it is also necessary to give serious consideration to the process equipment and pipeline layout, etc., and optimize the design of vertical support between columns, which has resulted in two options:

 

Program 1: Vertical support is laid in some larger equipment load bearing position, but the influence of the process is more serious, can only play a supporting role for the belt layer of 34.4m, the roof can not be through.

 

Scheme 2: The vertical support between columns is not set in the relevant columns of the transverse frame, so that the arrangement of the process can be more powerful. The model parameters of these two options need to be compared by specialized software, and it is found that the feasibility of the first option is stronger through comparison, and it has a significant effect in the improvement of the structural performance of the plant. Therefore, the vertical support between columns of plant steel structure can be better optimized by using the first scheme. The design effect can be analyzed by specialized software as shown in Table 1 below. The overall structural performance of the plant can be effectively improved under seismic action, and the torsional effect can be significantly improved by seismic action.

 

2.2.2 Optimized design of support section

 

The horizontal loading capacity of steel structure to resist earthquake can be improved by vertical bracing, and the rods are the most easy to yield support under seismic action. Therefore, in order to increase the stability of the support, the design strength of the longitudinal inter-column support section needs to be increased. In the design of the support components, not with the larger section the safer, if the support remains unchanged, need to reasonably control the relevant parameters, need to increase the utilization rate of the support section up, so as to reasonably control the support components, improve the economic performance of the project.

 

3 Summary

 

In the construction of steel single-frame thermal power plant plant, it is necessary to design a reasonable design scheme, but also need to optimize the design scheme, so as to improve the structural performance of the plant, to ensure that the thermal power plant can successfully complete the production targets.