scholarly journals Study on variable condition model for steam turbine based on internal and external characteristics

2022 ◽  
Vol 355 ◽  
pp. 03071
Author(s):  
Gang Liu ◽  
Guang Yu ◽  
Qingyuan Xue

It is not easy to carry out the detailed variable condition calculation of steam turbine in engineering application. In this paper, a variable condition calculation model based on the internal and external characteristics of steam turbine is proposed, and a variable condition calculation model of constant power and constant flow is established. The model is applied to calculate 75% THA, 50%THA, typical industrial and heating extraction conditions of a subcritical 330 MW unit. The error is small compared with the design value, and the calculation accuracy meets the requirements. The results show that the model has high accuracy and can meet the requirements of engineering application.

2013 ◽  
Vol 791-793 ◽  
pp. 1073-1076
Author(s):  
Ming Yang ◽  
Shi Ping Zhao ◽  
Han Ping Wang ◽  
Lin Peng Wang ◽  
Shao Zhu Wang

The unsteady hydrodynamic accurate calculation is the premise of submerged body trajectory design and maneuverability design. Calculation model of submerged body unsteady hydrodynamic with the movement in the longitudinal plane was established, which based on unsteady three-dimensional incompressible fluid dynamics theory. Variable speed translational and variable angular velocity of the pitching motion in the longitudinal plane of submerged body was achieved by dynamic mesh method. The unsteady hydrodynamic could be obtained by model under the premise of good quality grid by the results. Modeling methods can learn from other similar problems, which has engineering application value.


2012 ◽  
Vol 550-553 ◽  
pp. 3160-3163
Author(s):  
Yong Guang Ma ◽  
Ning Ran ◽  
Bing Zheng

For the low pressure (LP) cylinder of a steam turbine, computation of the exhaust enthalpy is an important part in thermal power generating unit performance monitoring. A new online model for calculating the exhaust enthalpy was proposed aiming at the limitation of existing online calculation model for calculating the enthalpy of steam turbine LP cylinder exhaust steam. This model treats LP cylinder, condenser and corresponding heater as an open system, according to the energy balance equation of this open system, figuring out its exhaust enthalpy. Calculation results of typical steam turbine show that: in a large load change range, the results are close to thermal experimental value, the accuracy is similar to energy balance method.


2013 ◽  
Author(s):  
Likun Zheng ◽  
Chang Chen ◽  
Danmei Xie ◽  
Hengliang Zhang ◽  
Yanzhi Yu

For condensing turbine, steam exhaust point is in wet steam area. The exhaust steam humidity of steam turbine is difficult to get due to lacking of effective measuring method. Calculation of exhaust steam humidity has always been one of the key parts of the analysis of thermal power units. The main factors affecting exhaust steam humidity are turbine load and turbine exhaust pressure etc, and they are of non-linearity. This paper develops a calculation method to calculate exhaust steam humidity based on BP neural network. Taking a N1000-25/600/600 ultra-supercritical (USC) steam turbine as an example, the exhaust steam humidity is calculated and the results show that the method has a good accuracy to meet the needs of the engineering application.


2014 ◽  
Vol 971-973 ◽  
pp. 848-851 ◽  
Author(s):  
Jian Jie Tang ◽  
Jin Yuan Tang

A valid mathematic model is introduced to study the calculation of gear meshing transmission error, which is based on the manufacturing error and gear teeth deformation. Subsequently, take a pair of specific gear for example;The transmission error curves are obtained by the calculation model. The results show great consistency with the curves from Romax software, which indicates the validity and high accuracy of the mathematic model presented above. And it can be found that the shape change of transmission error curves affected mainly by the pitch error under the same conditions as the precision.


Author(s):  
Kazutaka Hayashi ◽  
Hiroyuki Shiraiwa ◽  
Hiroyuki Yamada ◽  
Susumu Nakano ◽  
Kuniyoshi Tsubouchi

A prototype machine for a 150 kW class two-stage radial inflow condensing steam turbine system has been constructed. This turbine system was proposed for use in the bottoming cycle for 2.4 MW class gas engine systems, increasing the total electrical efficiency of the system by more than 2%. The gross power output of the prototype machine on the generator end was 150kW, and the net power output on the grid end which includes electrical consumption of the auxiliaries was 135kW. Then, the total electrical efficiency of the system was increased from 41.6% to 43.9%. The two-stage inflow condensing turbine system was applied to increase output power under the supplied steam conditions from the exhaust heat of the gas engines. This is the first application of the two-stage condensing turbine system for radial inflow steam turbines. The blade profiles of both high- and low-pressure turbines were designed with the consideration that the thrust does not exceed 300 N at the rated rotational speed. Load tests were carried out to demonstrate the performance of the prototype machine and stable output of 150 kW on the generator end was obtained at the rated rotational speed of 51,000 rpm. Measurement results showed that adiabatic efficiency of the high-pressure turbine was less than the design value, and that of the low-pressure turbine was about 80% which was almost the same as the design value. Thrust acting on the generator rotor at the rated output power was lower than 300 N. Despite a lack of high-pressure turbine efficiency, total thermal efficiency was 10.5% and this value would be enough to improve the total thermal efficiency of a distributed power system combined with this turbine system.


2013 ◽  
Vol 680 ◽  
pp. 597-601
Author(s):  
Zhang Yong Li ◽  
Xiao Bo Chen ◽  
Rui Leng ◽  
Fei Ba Chang

This paper put forward a new kind of motion energy expenditure calculation model that combine movement heart rate, acceleration, height, gender, age, weight and other personalized parameters. In this model, using heart rate and personalized parameters to calculate the based energy consumption (BEE). Using acceleration and personalized parameters to calculate the movement work (EEact). The experimental results show that this method has a high accuracy in movement energy expenditure. So using this method can eliminate the contradiction between measurement accuracy and measuring cost.


2013 ◽  
Vol 405-408 ◽  
pp. 1427-1430
Author(s):  
Jin Song Gui ◽  
Yu Fu ◽  
En Kai Bi

Lattice type steel sheet pile wharf is a new type of wharf structure, which is increasingly and widely used, but its structure is complicated, and the calculation theory is not perfect. This paper uses the general finite element software ABAQUS to establish the finite element numerical calculation model of grid shape steel sheet pile structure. The result was deeply researched and analysed,so some useful conclusions are drawn that can be used as references in the engineering application.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Fei Gan ◽  
XiaoMing Ye ◽  
Ke Yin ◽  
Meilin Li ◽  
Jing Bi

A new type of retaining wall, the self-balance retaining wall, is introduced in this paper. Based on the stress analysis, the calculation model and method are advanced about the retaining wall. A comparative analysis related to traditional retaining wall is carried out on stress and cost combining with an actual project. The results show that the idea of using upper gravity retaining wall as the resistance of lower retaining wall is clever and reasonable that the self-balance retaining wall has a very wide scope of application relying on the anchor tensile conditions rarely and that the self-balance retaining wall has a great economic value with low cost. The cost of the self-balance retaining wall is 50% compared with the cantilever pile retaining wall under the same conditions which has a good economic effect and application prospect.


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