scholarly journals Innovative design of exhaust enthalpy algorithm for small turbine

2021 ◽  
Vol 2083 (3) ◽  
pp. 032020
Author(s):  
Lingkai Zhu ◽  
Qian Wang ◽  
Song Gao ◽  
Ziwei Zhong ◽  
Panfeng Shang ◽  
...  
Keyword(s):  
Steam Turbine ◽  
Steam Pressure ◽  
Feed Water ◽  
Water Pump ◽  
Comprehensive Understanding ◽  
Safe Operation ◽  
Innovative Design ◽  
Pump Inlet ◽  
Reliable Basis ◽  
Small Measurement Error

Abstract This paper presents a method to determine the exhaust enthalpy of small steam turbine. Starting from the feed water pump group, the feed water pump and small steam turbine are studied as a whole. Based on the thermodynamic method, the efficiency of the feed water pump is obtained separately, and then the efficiency and exhaust enthalpy of the small steam turbine are deduced. This method only needs to measure the inlet and outlet pressure, temperature, feed water flow of feed water pump, inlet steam pressure, temperature and flow of small turbine. It has the advantages of less measurement parameters, low measurement cost and small measurement error. It provides a reliable basis for a comprehensive understanding of the performance of small steam turbine and guiding its economic and safe operation.

scholarly journals Application of a Two-Stage Steam Jet Injector Unit for Latent Heat Recovery of a Marine Steam Turbine Propulsion Plant

2021 ◽  
Vol 11 (12) ◽  
pp. 5511
Author(s):  
Szymon Grzesiak ◽  
Andrzej Adamkiewicz
Keyword(s):  
Steam Turbine ◽  
Steam Pressure ◽  
Relative Increase ◽  
Parameters Optimization ◽  
Feed Water ◽  
Water Heating ◽  
Two Stage ◽  
Heating Systems ◽  
Heating Steam ◽  
Numerical Research

The paper presents the results of the numerical research of the steam jet injector applications for the regenerative feed water heating systems of marine steam turbine propulsion plants. The analysis shows that the use of a single injector for a single heat exchanger results in a relative increase in the thermal efficiency of the plant by 0.6–0.9%. The analysis also indicates the legitimacy of the usage of multistage feed water heating systems, which would enable the operating parameters optimization of the injectors. The obtained steam pressure up to the value of 1.8 barA allows for the heating of the feed water up to 110 °C. For higher degrees of feed water heating in the heat exchangers, it is necessary to supply heating steam of higher pressure. Therefore, the usage of two-stage steam jet injector units was considered advisable for the analyses.

scholarly journals Influence of reheat pressure on reheat cycle economy

2021 ◽  
Vol 267 ◽  
pp. 01053
Author(s):  
Yarong Wang ◽  
Peirong Wang
Keyword(s):  
Steam Turbine ◽  
Steam Pressure ◽  
Correct Choice ◽  
Correct Selection ◽  
Safe Operation ◽  
Steam Power ◽  
Power Cycle ◽  
Cycle Economy ◽  
Selection Of ◽  
Turbine Exhaust

After steam expands to a certain intermediate pressure in steam turbine, it is led out of steam turbine and sent to reheater of boiler. The steam is heated to the initial temperature by constant pressure in the reheater. After that, the steam is introduced into the steam turbine and continues to expand to the exhaust steam pressure. The steam after work enters the condenser for cooling and heat release. Such a steam power cycle is a reheat cycle. The purpose of reheat cycle is to solve the contradiction that the dryness of exhaust steam decreases after the application of high parameters in steam power cycle. Through theoretical study and qualitative analysis, we know that the correct selection of reheat pressure can not only improve the steam turbine exhaust dryness, but also improve the thermal efficiency of the cycle. Reheat pressure is very important to the economy of reheat cycle and the safe operation of equipment. The correct choice of reheat pressure will affect the economy of the whole cycle.

scholarly journals Energy Power Losses and Efficiency of Low Power Steam Turbine for the Main Feed Water Pump Drive in the Marine Steam Propulsion System

2018 ◽  
Vol 54 (1) ◽  
pp. 37-51
Author(s):  
Vedran Mrzljak ◽  
Jasna Prpić-Oršić ◽  
Igro Poljak
Keyword(s):  
Energy Efficiency ◽  
Low Power ◽  
Steam Turbine ◽  
Feed Water ◽  
Water Pump ◽  
Efficiency Change ◽  
Power Losses ◽  
Specific Entropy ◽  
Power Turbine ◽  
Wide Range

Steam turbine for the main feed water pump (MFP) drive is a low power turbine, for which energy power losses and energy efficiency analysis are presented in this paper. The MFP steam turbine analysis has been performed within a wide range of turbine loads. The influence of steam specific entropy increment of the real (polytropic) steam expansion upon the MFP turbine energy power losses and energy efficiency has been investigated. During all the observed loads MFP steam turbine energy power losses were in the range between 346.2 kW and 411.4 kW. The MFP steam turbine energy power losses and energy efficiency were most significantly influenced by the steam specific entropy increment. Change in the steam specific entropy increment is directly proportional to the change in MFP turbine energy power losses, while the change in the steam specific entropy increment is reversely proportional to the MFP turbine energy efficiency change. For the observed turbine loads, the MFP steam turbine energy efficiency was in the range between 46.83% and 51.01%.

The Efficiency Analysis of Steam Turbine-Driven Feed Water Pump

2013 ◽  
Vol 401-403 ◽  
pp. 312-315
Author(s):  
Ming Fu Liu ◽  
Gai Lin Lu
Keyword(s):  
Steam Turbine ◽  
Mathematic Model ◽  
Feed Water ◽  
Water Pump ◽  
Feed Pump ◽  
Flow Loss ◽  
Working Principle ◽  
The Difference ◽  
Multistage Pump ◽  
The Relationship

The text introduces the structure of steam turbine-driven feed water pump briefly, analyzes the difference between steam turbine-driven feed water pump and electrically driven feed pump, and expresses the working principle of centrifugal pump. Besides, it researchs the advantage of raising head of multistage pump by the analysis of a three-level feed pump, states that pump power loss can be divided into mechanical loss, flow loss and volumetric loss respectively and sets up the mathematic model with the power and efficiency and concludes the calculation method of the overall efficiency of multistage pump and analyzes the relationship between the various power losses and rotational speed and presents specific measures to improve the efficiency.

Thermal System Optimization and Energy Grade Analysis of 700°C HUSC Steam Turbine Using a EC System

2018 ◽  
Author(s):  
Haiyu He ◽  
Tao Chen ◽  
Shiwang Fan ◽  
Xiaohua Xia ◽  
Fang Zhang ◽  
...  
Keyword(s):  
Steam Turbine ◽  
Load Condition ◽  
System Optimization ◽  
Thermodynamic System ◽  
Feed Water ◽  
Steam Temperature ◽  
Efficient System ◽  
Cycle System ◽  
System Solution ◽  
Main Steam

700°C High Ultra Supercritical (HUSC) technology is taken into account as a more efficient clean coal-fired power generation technology which can achieve higher efficiency and less CO2 emission. With the increase of the main steam and reheat steam temperature, the temperature of regenerative extraction increased accordingly. This not only means higher investment cost and higher unreliability of power plant, but also leads to a great reduction of energy grade efficiency. To solve the above-mentioned problem, we introduce a novel system, called echelon cycle system (EC system). In EC system, a BEST (Backpressure Extraction Steam Turbine) is added, which provides power for feed-water pump and steam for feed-water heaters. The steam source of high temperature regenerative extractions is switched from main turbine to BEST, and the steam source of BEST is cold-reheat. Hence the highest regenerative extraction steam temperature decreased accordingly. EC system has been demonstrated to be a more efficient system by exergy theory[1] and energy grade theory. Three types of EC system are proposed in this paper. Thermal performance calculation of these three types of EC system under rated-load condition and part-load condition is carried out to evaluate and compare the economy of system. In order to obtain a more appropriate thermodynamic system solution, safety and restriction should also be given sufficient consideration. Meanwhile, the matrix solution method for energy grade efficiency of EC system is derived in this paper. Finally, energy grade theory is used to analyze how different schemes cause different hate rate profits.

Low Pressure Steam Turbine Exhaust Flow: Part 1 — CFD Coupling of LP Turbine and Condenser Neck

2016 ◽  
Author(s):  
Peter Stein ◽  
Dirk Telschow ◽  
Frederic Lamarque ◽  
Nuncio Colitto
Keyword(s):  
Steam Turbine ◽  
Measurement Data ◽  
Low Pressure ◽  
Computational Time ◽  
Feed Water ◽  
Cfd Modelling ◽  
Design Changes ◽  
Plant Level ◽  
Lp Turbine ◽  
Modelling Approach

Since many years the diffuser and exhaust of low pressure (LP) turbines have been in the focus of turbine development and accordingly broadly discussed within the scientific community. The pressure recovery gained within the diffuser significantly contributes to the turbine performance and therefore plenty of care is taken in investigations of the flow as well as optimization within this part of the turbine. However on a plant level the component following the LP turbine is the condenser, which is connected by the condenser neck. Typically the condenser neck is not fully designed to provide additional enthalpy recovery. Due to plant arrangement reasons, often it is full of built-ins like stiffening struts, feed-water heaters, extraction pipes, steam dump devices and others. It is vital to minimize the pressure losses across the condenser neck, in order to keep performance benefit, previously gained within the diffuser. As a general rule, each mbar of total pressure loss in a condenser neck may reduce the gross power output up to 0.1%. While turbines usually follow a modular approach, the condenser is typically designed plant specific. Therefore, on a plant level it is crucial to identify and evaluate the loss contributors and develop processes and tools which allow an accurate and efficient design process for an optimized condenser neck design. This needs to be performed as a coupled modelling approach, as both, turbine and condenser flow interact with each other. 3-D CFD tools enable a deep insight into the flow field and help to locally optimize the design, as they help to identify local losses and this even for small geometrical design changes. Unfortunately these tools are costly with respect to computational time and resources, if they are used to analyze a full condenser neck with all built-ins. Here 1-D modelling approaches can help to close the gap, as they can provide fast feedback, e.g. in a project tender phase, or can allow to quickly analyze design changes. For this they need a proper calibration and validation. This publication discusses the CFD modelling of a LP steam turbine coupled to a condenser neck and the validity of such calculations against measurement data. In the second publication (Part 2) a simplification of the gained information to a 1-D modelling approach will be discussed.

scholarly journals Reheat and Regenerative Gas Turbines for Feed Water Repowering of Steam Power Plant

1995 ◽  
Author(s):  
G. Negri di Montenegro ◽  
M. Gambini ◽  
A. Peretto
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Flow Rate ◽  
Gas Turbines ◽  
Power Plants ◽  
Feed Water ◽  
Brayton Cycle ◽  
Energy Integration ◽  
Steam Power ◽  
Steam Power Plants

This study is concerned with the repowering of existing steam power plants (SPP) by gas turbine (GT) units. The energy integration between SPP and GT is analyzed taking into particular account the employment of simple and complex cycle gas turbines. With regard to this, three different gas turbine has been considered: simple Brayton cycle, regenerative cycle and reheat cycle. Each of these cycles has been considered for feed water repowering of three different existing steam power plants. Moreover, the energy integration between the above plants has been analyzed taking into account three different assumptions for the SPP off-design conditions. In particular it has been established to keep the nominal value for steam turbine power output or for steam flow-rate at the steam turbine inlet or, finally, for steam flow-rate in the condenser. The numerical analysis has been carried out by the employment of numerical models regarding SPP and GT, developed by the authors. These models have been here properly connected to evaluate the performance of the repowered plants. The results of the investigation have revealed the interest of considering the use of complex cycle gas turbines, especially reheat cycles, for the feed water repowering of steam power plants. It should be taken into account that these energy advantages are determined by a repowering solution, i.e. feed water repowering which, although it is attractive for its simplicity, do not generally allows, with Brayton cycle, a better exploitation of the energy system integration in comparison with other repowering solutions. Besides these energy considerations, an analysis on the effects induced by repowering in the working parameters of existing components is also explained.

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